EXHIBIT 32


      CERTIFICATION OF CHIEF EXECUTIVE OFFICER AND CHIEF FINANCIAL OFFICER
            PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

      I, Thian Hoo Tan, 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 Komag, Incorporated on Form 10-K for the fiscal year ended December
28, 2003 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
fairly presents in all material respects the financial condition and results of
operations of Komag, Incorporated.

            DATE:  March 5, 2004                   BY: /s/  Thian Hoo Tan
                   --------------                      --------------------

                                                   Thian Hoo Tan
                                                   Chief Executive Officer


      I, Kathleen A. Bayless, 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 Komag, Incorporated on Form 10-K for the fiscal year ended
December 28, 2003 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 fairly presents in all material respects the financial condition and
results of operations of Komag, Incorporated.


            DATE:  March 5, 2004                   BY: /s/  Kathleen A. Bayless
                   --------------                      -----------------

                                                   Kathleen A. Bayless
                                                   Chief Financial Officer



      This certification accompanies this Report on Form 10-K pursuant to
Section 906 of the Sarbanes-Oxley Act of 2002 and shall not, except to the
extent required by such Act, be deemed filed by Komag, Incorporated for purposes
of Section 18 of the Security Exchange Act of 1934, as amended. A signed
original of this written statement required by Section 906 has been provided to
Komag, Incorporated and will be retained by Komag, Incorporated and furnished to
the Securities and Exchange Commission or its staff upon request.