EXHIBIT 99.1 CERTIFICATION OF CHIEF EXECUTIVE OFFICER AND CHIEF FINANCIAL OFFICER PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 I, James J. Kim, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual Report of Amkor Technology, Inc. on Form 10-K/A for the year ended December 31, 2002 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that information contained in such Form 10-K/A fairly presents in all material respects the financial condition and results of operations of Amkor Technology, Inc. By: /s/ James J. Kim _________________________ Name: James J. Kim Title: Chief Executive Officer I, Kenneth T. Joyce, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual Report of Amkor Technology, Inc. on Form 10-K/A for the year ended December 31, 2002 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that information contained in such Form 10-K/A fairly presents in all material respects the financial condition and results of operations of Amkor Technology, Inc. By: /s/ Kenneth T. Joyce _________________________ Name: Kenneth T. Joyce Title: Chief Financial Officer Signed originals of these written statements required by Section 906 have been provided to Amkor Technology, Inc., and will be retained by Amkor Technology, Inc., and furnished to the Securities and Exchange Commission or its staff upon request.