Exhibit 21.1

SUBSIDIARIES OF REGISTRANT
AS OF OCTOBER 31, 2006

		Percentage of
		Voting Securities
		Owned by
	State of	Immediate
Name	Incorporation	Parent
ABM Industries Incorporated	Delaware	Registrant
(*) ABM Facility Services Company	California		100	%
ABM Engineering Services Company	California		100	%
ABM CMS, Inc. **	California		100	%
ABM Janitorial Services, Inc.	Delaware		100	%
ABM Co. of Boston	California		100	%
ABM Janitorial Northeast, Inc.	California		100	%
ABM Janitorial — Northern California	California		100	%
ABM Mid-Atlantic, Inc.	California		100	%
American Building Maintenance Co.	California		100	%
American Building Maintenance Co. — West	California		100	%
American Building Maintenance Co. of Georgia	California		100	%
American Building Maintenance Co. of Hawaii	California		100	%
Allied Maintenance Services, Inc.	Hawaii		100	%
American Building Maintenance Co. of Kentucky	California		100	%
American Building Maintenance Co. of New York	California		100	%
American Building Maintenance Co. of New York — Manhattan	California		100	%
Bonded Maintenance Company	Texas		100	%
Bradford Building Services, Inc.	California		100	%
Servall Services, Inc.	Texas		100	%
ABM Janitorial Services Co., Ltd.	Brit. Columbia		100	%
ABM Payroll Service, Inc.	California		100	%
ABM Security Services, Inc.	California		100	%
SSA Security, Inc.	California		100	%
Elite Security, Inc.	California		100	%
American Public Services	California		100	%
Ampco Pacific Airpark, LLC***	California		60	%
Ampco System Parking	California		100	%
Amtech Energy Services**	California		100	%
Amtech Lighting & Electrical Services	California		100	%
Amtech Lighting Services	California		100	%
Amtech Lighting Services of the Midwest	California		100	%
Amtech Reliable Elevator Company of Texas**	Texas		100	%
Beehive Parking, Inc.**	Utah		100	%
Canadian Building Maintenance Company, Ltd.	Brit. Columbia		100	%
Supreme Building Maintenance, Ltd.	Brit. Columbia		100	%
System Parking, Inc.	California		100	%

(*)	Subsidiary relationship to registrant or to subsidiary parents shown by progressive indentation.
**	Inactive companies.
***	A Limited Partnership.