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UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON , D.C. 20549 FORM 20 - F REGISTRATION STATEMENT PURSUANT TO SECTION 12 ( b ) OR ( g ) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 OR ( Mark One ) ☐ 冈 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 ☐ OR SHELL COMPANY REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of event requiring this shell company report For the transition period from Title of each class American Depositary Shares , each representing 5 Common Shares to Commission file number 001-15128 United Microelectronics Corporation ( Exact name of Registrant as specified in its charter ) N / A ( Translation of Registrant's name into English ) Taiwan , Republic of China ( Jurisdiction of incorporation or organization ) No. 3 Li - Hsin Road II , Hsinchu Science Park , Hsinchu City , Taiwan , Republic of China ( Address of principal executive offices ) Chitung Liu , Senior Vice President & Chief Financial Officer Telephone : + 886-2-2658-9168 / Email : ir@umc.com 8F , No. 68 , Section 1 , Neihu Road . , Taipei 11493 , Taiwan R.O.C. ( Name , Telephone , E - mail and / or Facsimile number and Address of Company Contact Person ) Securities registered or to be registered pursuant to Section 12 ( b ) of the Act . Trading Symbol ( s ) UMC Securities registered or to be registered pursuant to Section 12 ( g ) of the Act . None ( Title of Class ) Securities for which there is a reporting obligation pursuant to Section 15 ( d ) of the Act . None ( Title of Class ) Indicate the number of outstanding shares f each of the issuer's classes of capital or common stock as of the close of the period covered by the annual report . 12,422,401,493 Common Shares of Registrant issued and outstanding as of December 31 , 2020 Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes No Name of each exchange on which registered New York Stock Exchange If this report is an annual or transition report , indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15 ( d ) of the Securities Exchange Act of 1934. Yes □ No Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes No Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T ( $ 232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit and post such files ) . Yes No Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , or an emerging growth company . See definition of " large accelerated filer , " " accelerated filer , " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . Large accelerated filer Accelerated filer Emerging growth company Non - accelerated filer > ☐ If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP , indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . + The term " new or revised financial accounting standard " refers to any update issued by the Financial Accounting Standards Board to its Accounting Standards Codification after April 5 , 2012 . Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing : U.S. GAAP International Financial Reporting Standards as issued by the International Accounting Standards Board If " Other " has been checked in response to the previous question , indicate by check mark which financial statement item the registrant has elected to follow . If this is an annual report , indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Securities Exchange Act of 1934 ) . Item 17 Item 18 Yes No Other