EXHIBIT 32.2

CERTIFICATION OF CHIEF FINANCIAL OFFICER
PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

     The undersigned, being the Chief Financial Officer of Archstone-Smith Operating Trust, a Maryland real estate investment trust (the “Issuer”), hereby certifies, that the Quarterly Report on Form 10-Q (the “Periodic Report”) of the Issuer for the quarter ended March 31, 2007 which accompanies this certification, fully complies with the requirements of Section 13(a) of the Securities Exchange Act of 1934 (15 U.S.C. §78m(a)) and that the information contained in the Periodic Report fairly presents, in all material respects, the financial condition and results of operations of the Issuer.

Date: May 9, 2007

/s/ CHARLES E. MUELLER, JR.  

Charles E. Mueller, Jr., Chief Financial Officer