EXHIBIT 5

                   OPINION OF BROBECK, PHLEGER & HARRISON LLP

                                November 21, 2000

Credence Systems Corporation
215 Fourier Avenue

Fremont, CA  94539

                    Re:  Credence Systems Corporation Registration Statement on
                         Form S-8 for an Aggregate of 2,599,645 Shares of
                         Common Stock

Ladies and Gentlemen:

     We have acted as counsel to Credence Systems Corporation, a Delaware
corporation (the "Company"), in connection with the registration on Form S-8
(the "Registration Statement") under the Securities Act of 1933, as amended, of
an initial reserve of 500,000 shares of the Company's common stock ("Common
Stock") authorized for issuance under the Company's Supplemental Stock Option
Plan (the "Supplemental Plan"), an additional 1,837,189 shares of Common Stock
authorized for issuance under the Company's 1993 Stock Option Plan (the "Option
Plan"), and an additional 262,456 shares of Common Stock authorized for issuance
under the Company's Employee Stock Purchase Plan (the "Purchase Plan")
(collectively, the "Plans"). The foregoing shares of Common Stock authorized for
issuance under the Plan shall be hereinafter referred to as the "Shares."

     This opinion is being furnished in accordance with the requirements of Item
8 of Form S-8 and Item 601(b)(5)(i) of Regulation S-K.

     We have reviewed the Company's charter documents and the corporate
proceedings taken by the Company in connection with the establishment of the
Supplemental Plan and the amendment of the Option Plan and the Purchase
Plan to increase the number of shares of Common Stock issuable thereunder. Based
on such review, we are of the opinion that if, as and when the Shares are issued
and sold (and the consideration therefor received) pursuant to (a) the
provisions of stock option agreements duly authorized under the Supplemental
Plan and/or the Option Plan and in accordance with the Registration Statement
or (b) the provisions of duly authorized purchase rights granted under the
Purchase Plan and in accordance with the Registration Statement, such Shares
will be duly authorized, legally issued, fully paid and non-assessable shares of
Common Stock.

     We consent to the filing of this opinion letter as Exhibit 5.1 to the
Registration Statement.

     This opinion letter is rendered as of the date first written above and we
disclaim any obligation to advise you of facts, circumstances, events or
developments which hereafter may be brought to our attention and which may
alter, affect or modify the opinion expressed herein. Our opinion is expressly
limited to the matters set forth above and we render no opinion, whether by
implication or otherwise, as to any other matters relating to the Company, the
Plan or the Shares.

                         Very truly yours,


                         /s/ Brobeck, Phleger & Harrison LLP
                             BROBECK, PHLEGER & HARRISON LLP