Erp Operating LTD Partnership 10-Q 2006 Q3 Quarterly report

Exhibit 32.2

CERTIFICATION 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 of ERP Operating Limited Partnership (“ERPOP”) on Form 10-Q for the period ending September 30, 2006 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Donna Brandin, Chief Financial Officer of Equity Residential, general partner of ERPOP, certify, pursuant to 18.U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge:

(1)The Report fully complies with the requirements of section 13(a) or 15(d) 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 ERPOP.

/s/ Donna Brandin

Donna Brandin

Chief Financial Officer

of Equity Residential

November 6, 2006