Exhibit 23(b)
CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We hereby consent to the incorporation by reference in this Registration Statement on Form S-4
of KLA Tencor Corporation of our report dated July 25, 2005 relating to the financial statements,
financial statement schedule, managements assessment of the effectiveness of internal control over
financial reporting and the effectiveness of internal control over financial reporting, which
appears in ADE Corporations Annual Report on Form 10-K for the year ended April 30, 2005. We also
consent to the reference to us under the heading Experts in such Registration Statement.
/s/ PricewaterhouseCoopers, LLP
Boston, Massachusetts
March 15, 2006