Exhibit 23 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We hereby consent to the incorporation by reference in the Registration Statement on Form S-8 (No. 333-104155) of Penton Media, Inc. of our report dated April 14, 2005 relating to the financial statements and financial statement schedule, which appears in this Form 10-K. PricewaterhouseCoopers LLP Cleveland, Ohio April 15, 2005