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 Quarterly
Report of Komag, Incorporated on Form 10-Q for the quarterly period ended July
4, 2004 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-Q
fairly presents in all material respects the financial condition and results of
operations of Komag, Incorporated.

                                                     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
Quarterly Report of Komag, Incorporated on Form 10-Q for the quarterly period
ended July 4, 2004 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 10-Q fairly presents in all material respects the financial condition and
results of operations of Komag, Incorporated.

                                                     BY: /s/ Kathleen A. Bayless

                                                     Kathleen A. Bayless
                                                     Chief Financial Officer

      This certification accompanies this Report on Form 10-Q 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.