POWER OF ATTORNEY


      	KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes
      and appoints John Detwiler and Brian Sereda, and each of them, his true and lawful attorney-in-
      fact to:

      	1)  execute for and on behalf of the undersigned, in the undersigned's capacity as an
      officer and/or director of Credence System Corporation (the "Company"), any and all Forms 3, 4
      and 5 required to be filed by the undersigned in accordance with Section 16(a) of the Securities
      Exchange Act of 1934 and the rules thereunder;

      	2)  do and perform any and all acts for and on behalf of the undersigned which may be
      necessary or desirable to complete and execute any such Form 3, 4 or 5 and timely file such form
      with the United States Securities and Exchange Commission and any stock exchange or similar
      authority; and

      	3)  take any other action of any type whatsoever in connection with the foregoing which,
      in the opinion of the attorney-in-fact, may be of benefit to, in the best interest of, or legally
      required by, the undersigned, it being understood that the documents executed by such attorney-
      in-fact on behalf of the undersigned, pursuant to this Power of Attorney, shall be in such form
      and shall contain such terms and conditions as such attorney-in-fact may approve in his
      discretion.

      	The undersigned hereby grants to each such attorney-in-fact full power and authority to
      do and perform all and every act and thing whatsoever requisite, necessary, and proper to be
      done in the exercise of any of the rights and powers herein granted, as fully to all intents and
      purposes as the undersigned might or could do if personally present with full power of
      substitution or revocation, hereby ratifying and confirming all that such attorney-in-fact, or his
      substitute or substitutes, shall lawfully do or cause to be done by virtue of this Power of Attorney
      and the rights and powers herein granted.  The undersigned acknowledges that no such attorney-
      in-fact, in serving in such capacity at the request of the undersigned, is hereby assuming, nor is
      the Company hereby assuming, any of the undersigned's responsibilities to comply with Section
      16 of the Securities and Exchange Act of 1934.

      	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 the securities issued by the Company, unless earlier revoked by the undersigned
      in a signed writing delivered to the foregoing attorney-in-fact.

      	IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
      executed as of the 24th day of October, 2004.


      /s/ William G. Howard
      William G. Howard