POWER OF ATTORNEY

The undersigned, as a Section 16 reporting person of
Komag Incorporated (the "Company"), hereby constitutes and appoints Jan
Schwartz and Kathleen A. Bayless, and each of them, the undersigned's true
and lawful attorney-in-fact to:

1.	complete and execute Forms 3, 4
and 5 and other forms and all amendments thereto as such attorney-in-fact
shall in his or her discretion determine to be required or advisable
pursuant to Section 16 of the Securities Exchange Act of 1934 (as amended)
and the rules and regulations promulgated thereunder, or any successor laws
and regulations, as a consequence of the undersigned's ownership,
acquisition or disposition of securities of the Company; and

2. do all
acts necessary in order to file such forms with the Securities and Exchange
Commission, any securities exchange or national association, the Company
and such other person or agency as the attorney-in-fact shall deem
appropriate.

The undersigned hereby ratifies and confirms all that
said attorneys-in-fact and agents shall do or cause to be done by virtue
hereof.  The undersigned acknowledges that the foregoing attorneys-in-fact,
in serving in such capacity at the request of the undersigned, are not
assuming, nor is the Company assuming, any of the undersigned's
responsibilities to comply with Section 16 of the Securities Exchange Act
of 1934 (as amended).

This Power of Attorney shall remain in full
force and effect until the undersigned is no longer required to file Forms
3, 4, and 5 with respect to the undersigned's holdings of and transactions
in securities issued by the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the Company and the foregoing
attorneys-in-fact.

	IN WITNESS WHEREOF, the undersigned has caused
this Power of Attorney to be executed as of this 28th day of April, 2003.



Signature: 	/s/ Kenneth Swimm

Print Name: Kenneth Swimm