Abstract: A vane pump for use in a power steering device comprising a pump housing receiving a cam ring therein. A pair of side plates are disposed at opposite side of the cam ring in contact relationship therewith. A pump rotor rotatable integrally with a drive shaft is received in an internal cam bore of the cam ring. An end cover is secured to the pump housing in contact relationship with one of the side plates to cover an open end of the pump housing. A first positioning pin is fitted at one end thereof into an inner end wall of the pump housing for positioning the first and second side plates in a circumferential direction. A second positioning pin is fitted at one end thereof into one of the first and second side plates for positioning the cam ring in the circumferential direction.