Exhibit 99.1 CERTIFICATION OF CEO AND CFO PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of Public Storage Properties IV, Ltd. (the "Partnership") for the quarterly period ended March 31, 2003 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), Ronald L. Havner, Jr., as Chief Executive Officer of Public Storage, Inc., and John Reyes, as Chief Financial Officer of Public Storage, Inc., each hereby certifies, pursuant to 18 U.S.C.ss.1350, as adopted pursuant toss.906 of the Sarbanes-Oxley Act of 2002, that: (1) The Report fully complies with the requirements of Section 13(a) of the Securities Exchange Act of 1934; and (2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Partnership. /s/ Ronald L. Havner, Jr. - ------------------------------------ Name: Ronald L. Havner, Jr. Title: Chief Executive Officer of Public Storage, Inc., Corporate General Partner Date: May 15, 2003 /s/ John Reyes - ------------------------------------ Name: John Reyes Title: Chief Financial Officer of Public Storage, Inc., Corporate General Partner Date: May 15, 2003 This certification accompanies the Report pursuant to ss. 906 of the Sarbanes-Oxley Act of 2002 and shall not, except to the extent required by the Sarbanes-Oxley Act of 2002, be deemed filed by the Partnership for purposes of ss.18 of the Securities Exchange Act of 1934, as amended.