Independent Auditor's Review Report Based on a report originally issued in Korean (Form 6-K)

Independent Auditor's Review Report

Based on a report originally issued in Korean

The Shareholders and Board of Directors

Korea Electric Power Corporation:

We have reviewed the accompanying consolidated interim financial statements of Korea Electric Power Corporation (the 'Company') and its subsidiaries (collectively referred to as the 'Group'), which comprise the consolidated interim statement of financial position as of June 30, 2021, and the related consolidated interim statements of comprehensive income (loss) for the three-month and six-month periods ended June 30, 2021 and 2020, consolidated interim statements of changes in equity and consolidated interim statements of cash flows for the six-month periods then ended June 30, 2021 and 2020, and a summary of significant accounting policies and other explanatory information.

Management's Responsibility for the Consolidated Interim Financial Statements

Management is responsible for the preparation and presentation of these consolidated interim financial statements in accordance with Korean International Financial Reporting Standard (KIFRS) 1034 Interim Financial Reporting, and for such internal control as management determines is necessary to enable the preparation of interim financial statements that are free from material misstatement, whether due to fraud or error.

Auditor's Responsibility

Our responsibility is to express a conclusion on these consolidated interim financial statements based on our review. We conducted our review in accordance with the Review Standards for Quarterly and Semiannual Financial Statements established by the Securities and Futures Commission of the Republic of Korea. A review of interim financial information consists of making inquiries, primarily of persons responsible for financial and accounting matters, and applying analytical and other review procedures. A review is substantially less in scope than an audit conducted in accordance with Korean Auditing Standards (KGAAS) and, consequently, does not enable us to obtain assurance that we would become aware of all significant matters that might be identified in an audit. Accordingly, we do not express an audit opinion.

Conclusion

Based on our review, nothing has come to our attention that causes us to believe that the accompanying consolidated interim financial statements are not prepared, in all material respects, in accordance with KIFRS 1034 'Interim Financial Reporting'.

Other Matter

We have audited the consolidated statement of financial position of the Group as of December 31, 2020, and the related consolidated statement of comprehensive income (loss), consolidated statement of changes in equity and consolidated statement of cash flows for the year then ended (not presented herein) in accordance with KGAAS, and our report dated March 10, 2021 expressed an unqualified opinion thereon. The accompanying consolidated statement of financial position as of December 31, 2020 presented for comparative purposes, is not different, in all material respects, from the above audited consolidated statement of financial position.

August 17, 2021

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Consolidated Interim Statements of Financial Position

As of June 30, 2021 (Unaudited) and December 31, 2020

(Continued)

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Consolidated Interim Statements of Financial Position, Continued

As of June 30, 2021 (Unaudited) and December 31, 2020

The accompanying notes are an integral part of the consolidated interim financial statements.

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Consolidated Interim Statements of Comprehensive Income (Loss)

For the three and six-month periods ended June 30, 2021 and 2020 (Unaudited)

(Continued)

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Consolidated Interim Statements of Comprehensive Income (Loss), Continued

For the three and six-month periods ended June 30, 2021 and 2020 (Unaudited)

The accompanying notes are an integral part of the consolidated interim financial statements.

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Consolidated Interim Statements of Changes in Equity

For the six-month periods ended June 30, 2021 and 2020 (Unaudited)

(Continued)

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Consolidated Interim Statements of Changes in Equity, Continued

For the six-month periods ended June 30, 2021 and 2020 (Unaudited)

The accompanying notes are an integral part of the consolidated interim financial statements.

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Consolidated Interim Statements of Cash Flows

For the six-month periods ended June 30, 2021 and 2020 (Unaudited)

(Continued)

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Consolidated Interim Statements of Cash Flows, Continued

For the six-month periods ended June 30, 2021 and 2020 (Unaudited)

The accompanying notes are an integral part of the consolidated interim financial statements.

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Notes to the Consolidated Interim Financial Statements

June 30, 2021 and 2020 (Unaudited)

Korea Electric Power Corporation ('KEPCO') was incorporated on January 1, 1982 in accordance with the Korea Electric Power Corporation Act (the 'KEPCO Act') to engage in the generation, transmission and distribution of electricity and development of electric power resources in the Republic of Korea. KEPCO also provides power plant construction services. KEPCO's stock was first listed on the Korea Stock Exchange on August 10, 1989 and subsequently on the New York Stock Exchange on October 27, 1994 through its depository receipts. KEPCO's headquarter is located in Naju, Jeollanam-do.

As of June 30, 2021, KEPCO's share capital amounts to W3,209,820 million and KEPCO's shareholders are as follows:

In accordance with the Restructuring Plan enacted on January 21, 1999 by the Ministry of Trade, Industry and Energy, KEPCO spun off its power generation divisions on April 2, 2001, resulting in the establishment of six power generation subsidiaries.

These consolidated interim financial statements have been prepared in accordance with KIFRS 1034 'Interim Financial Reporting' as part of the period covered by KEPCO and subsidiaries' (the 'Group') KIFRS annual financial statements.

These consolidated financial statements have been prepared on the historical cost basis, except for the following material items in the consolidated statements of financial position:

These consolidated financial statements are presented in Korean won ('Won'), which is also the functional currency of KEPCO and most of the significant operating subsidiaries.

The preparation of the consolidated financial statements in conformity with KIFRS requires management to make judgments, estimates and assumptions that affect the application of accounting policies and the reported amounts of assets, liabilities, income and expenses. Actual results may differ from these estimates.

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Notes to the Consolidated Interim Financial Statements, Continued

June 30, 2021 and 2020 (Unaudited)

Estimates and underlying assumptions are reviewed on an ongoing basis. Revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected.

The followings are the key assumptions and other key sources of estimation uncertainty at the end of the reporting period, that have a significant risk of causing a material adjustment to the carrying amounts of assets and liabilities within the next financial year.

The Group reviews the estimated useful lives of property, plant and equipment at the end of each annual reporting period. Management's assumptions could affect the determination of estimated economic useful lives.

The Group records the fair value of estimated decommissioning costs as a liability in the period in which the Group incurs a legal obligation associated with the retirement of long-lived assets that result from acquisition, construction, development and/or normal use of the assets. The Group is required to record a liability for the dismantling (demolition) of nuclear power plants and disposal of spent fuel and low and intermediate radioactive wastes. The measurement of such liability is subject to change based on change in estimated cash flow, inflation rate, discount rate, and expected timing of decommissioning.

The Group recognizes deferred tax assets and liabilities based on the differences between the financial statement carrying amounts and the tax bases of assets and liabilities of each consolidated taxpaying entity. However, the amount of deferred tax assets may be different if the Group determines the estimated future taxable income is not sufficient to realize the deferred tax assets recognized.

The Group's accounting policies and disclosures require the measurement of fair values, for both financial and non-financial assets and liabilities. The Group has established control framework with respect to the measurement of fair values. The valuation team regularly reviews significant unobservable inputs and valuation adjustments.

If third party information, such as broker quotes or pricing services, is used to measure fair values, then the valuation team assesses the evidence obtained from the third parties to support the conclusion that such valuations meet the requirements of KIFRS including the level in the fair value hierarchy in which such valuation techniques should be classified.

When measuring the fair value of an asset or a liability, the Group uses market observable data as far as possible. Fair values are categorized into different levels in a fair value hierarchy based on the inputs used in the valuation techniques as follows.

If the inputs used to measure the fair value of an asset or a liability might be categorized in different levels of the fair value hierarchy, then the fair value measurement is categorized in its entirety in the same level of the fair value hierarchy as the lowest level input that is significant to the entire measurement. The Group recognizes transfers between levels of the fair value hierarchy at the end of the reporting period during which the change has occurred.

The Group offers its employees defined benefit plans. The cost of providing benefits is determined using the Projected Unit Credit Method, with actuarial valuations being carried out at the end of each reporting period. For actuarial valuations, certain inputs such as discount rates and future salary increases are estimated. Defined benefit plans contain significant uncertainties in estimations due to its long-term nature (refer to Note 25).

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Notes to the Consolidated Interim Financial Statements, Continued

June 30, 2021 and 2020 (Unaudited)

Electricity delivered but neither metered nor billed is estimated at the reporting date based on the volume of electricity delivered which can vary significantly as a result of customer usage patterns, customer mix, meter reading schedules, weather, and etc. Unbilled revenue recognized as of June 30, 2021 and 2020 are W1,397,539 million and W1,200,336 million, respectively.

The Group recognizes revenue over time using the cost-based input method which represents a faithful depiction of the Group's progress towards complete satisfaction of providing the power plant construction, which has been identified as a single performance obligation. In applying the cost-based input method, it is necessary to use estimates and assumptions related to the Group's efforts or inputs expected to be incurred. Cost incurred towards contract completion include costs associated with direct materials, labor, and other indirect costs related to contract performance. Judgment is required in estimating the costs expected to incur in completing the construction projects which involves estimating future materials, labor, contingencies and other related costs. Revenue is estimated based on the contractual amount; however, it can also be affected by uncertainties resulting from unexpected future events.

Changes in accounting standards effective from January 1, 2021 are as follows. The Group believes that these amendments have no significant impact on the Group's consolidated interim financial statements. The Group has not applied the new and revised standards in issue but not yet effective for the periods starting from January 1, 2021, even though the early adoption of these standards is possible.

Amendments to KIFRS 1109 'Financial Instruments', KIFRS 1039 'Financial Instruments: Recognition and Measurement', KIFRS 1107 'Financial Instruments: Disclosures', KIFRS 1104 'Insurance Contracts' and KIFRS 1116 'Lease' - Interest Rate Benchmark Reform Phase II

The amendments provide temporary reliefs which address the financial reporting effects when an interbank offered rate (IBOR) is replaced with an alternative nearly risk-free interest rate (RFR). The amendments include the following practical expedients:

The Group adopted the cost pass-through tariff system from January 1, 2021 with the approval of the Ministry of Trade, Industry and Energy (MOTIE) on December 17, 2020 and amended the supply contract and related enforcement regulations. The new system is applicable to electricity bills charged from January 1, 2021. The Group believes that the adoption of the aforementioned system has no significant impact on the Group's accounting policies, including 'Revenue from Contracts with Customers'.

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Notes to the Consolidated Interim Financial Statements, Continued

June 30, 2021 and 2020 (Unaudited)

The accounting policies applied by the Group in these consolidated interim financial statements are the same as those applied by the Group in its consolidated financial statements as of and for the year ended December 31, 2020, except for the changes described in Note 2.(5).

The Group's operating segments are its business components that generate discrete financial information that is reported to and regularly reviewed by chief operating decision makers of the Group including but not limited to the Chief Executive Officer, for the purpose of resource allocation and assessment of segment performance. The Group's reportable segments are 'Transmission and distribution', 'Electric power generation (Nuclear)', 'Electric power generation (Non-nuclear)', 'Plant maintenance & engineering service' and 'Others'; others mainly represent the business unit that manages the Group's foreign operations.

Segment operating profit (loss) is determined the same way that consolidated operating profit is determined under KIFRS without any adjustment for corporate allocations. The accounting policies used by each segment are consistent with the accounting policies used in the preparation of the consolidated financial statements. Segment assets and liabilities are determined based on separate financial statements of the entities instead of on a consolidated basis. There are various transactions between the reportable segments, including sales of property, plant and equipment and so on, that are conducted on an arm's-length basis at market prices that would be applicable to an independent third party. For subsidiaries which are in a different segment from that of its immediate parent company, their carrying amount in separate financial statements is eliminated in the consolidating adjustments in the tables below. In addition, consolidation adjustments in the table below include adjustments of the amount of investment in associates and joint ventures from the cost basis amount reflected in segment assets to that determined using equity method in the consolidated financial statements.

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Notes to the Consolidated Interim Financial Statements, Continued

June 30, 2021 and 2020 (Unaudited)

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Notes to the Consolidated Interim Financial Statements, Continued

June 30, 2021 and 2020 (Unaudited)

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Notes to the Consolidated Interim Financial Statements, Continued

June 30, 2021 and 2020 (Unaudited)

Electricity sales, the main operations of the Group, are conducted in the Republic of Korea. The following information on revenue from external customers and non-current assets is determined by the location of the customers and of the assets:

There is no single customer which accounts for 10% or more of the Group's revenue for the six-month periods ended June 30, 2021 and 2020.

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KOREA ELECTRIC POWER CORPORATION AND ITS SUBSIDIARIES

Notes to the Consolidated Interim Financial Statements, Continued

June 30, 2021 and 2020 (Unaudited)