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                                                                      Exhibit 24

                           DIRECTOR AND/OR OFFICER OF
                               PENTON MEDIA, INC.

                           ANNUAL REPORT ON FORM 10-K

                                POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS, that each of the undersigned directors and
officers of Penton Media, Inc., a Delaware corporation, hereby constitutes and
appoints Thomas L. Kemp, Daniel J. Ramella, Joseph G. NeCastro and Preston L.
Vice, and each of them, as the true and lawful attorney-in-fact or
attorneys-in-fact, with full power of substitution and revocation, for each of
the undersigned and in the name, place and stead of each of the undersigned, to
sign on behalf of each of the undersigned an Annual Report on Form 10-K for the
fiscal year ended December 31, 1999 pursuant to Section 13 of the Securities and
Exchange Act of 1934 and to sign any and all amendments to such Annual Report,
and to file the same, with all exhibits thereto, and other documents in
connection therewith, including, without limitation, a Form 12b-25, with the
Securities and Exchange Commission, granting to said attorney-in-fact or
attorneys-in-fact, and each of them, full power and authority to do so and
perform each and every act and thing requisite and necessary to be done in and
about the premises, as fully to all intents and purposes as the undersigned
might or could do in person, hereby ratifying and confirming all that said
attorney-in-fact or attorneys-in-fact or any of them or their substitute or
substitutes, may lawfully do or cause to be done by virtue hereof.

This Power of Attorney may be executed in multiple counterparts, each of which
shall be deemed an original with respect to the person executing it.

Executed as of this 15th day of March 1999.

/s/ THOMAS L. KEMP                              /s/ DANIEL J. RAMELLA
----------------------------------            ----------------------------------
Thomas L. Kemp                                 Daniel J. Ramella
Chief Executive Officer & Director             Director

/s/ JOSEPH G. NECASTRO                         /s/ ANTHONY DOWNS
----------------------------------            ----------------------------------
Joseph G. NeCastro                             Anthony Downs
Chief Financial Officer                        Director

/s/ JOCELYN A. BRADFORD                        /s/ WILLIAM J. FRIEND
----------------------------------            ----------------------------------
 Jocelyn A. Bradford                           William J. Friend
Director                                       Director

/s/ KING HARRIS                                /s/ JOAN W. HARRIS
----------------------------------            ----------------------------------
King Harris                                    Joan W. Harris
Director                                       Director

/s/ WILLIAM C. DONOHUE                         /s/  DON E. SCHULTZ
----------------------------------            ----------------------------------
William C. Donohue                             Don E. Schultz
Director                                       Director

/s/ JOHN J. MEEHAN                             /s/ RICHARD B. SWANK
----------------------------------            ----------------------------------
John J. Meehan                                 Richard B. Swank
Director                                       Director

/s/ EDWARD J. SCHWARTZ                         /s/ DOUGLAS GREENE
----------------------------------            ----------------------------------
Edward J. Schwartz                             Douglas Greene
Director                                       Director