EXHIBIT 23(a)
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 September 1, 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 KLA-Tencor Corporations Annual Report on Form 10-K for the year ended
June 30, 2005. We also consent to the reference to us under the heading Experts in such
Registration Statement.
/s/ PricewaterhouseCoopers, LLP
San Jose, California
March 16, 2006