A process cartridge detachably mountable to a main assembly of an image forming apparatus includes an electrophotographic photosensitive drum; a developing roller for developing an electrostatic latent image formed on the drum; a first frame supporting the drum; a second frame supporting the developing roller; a coupling member for coupling the first frame and the second frame such that developing roller and the drum contact each other or are spaced from each other; an urging member for urging the drum and the developing roller toward each other; a spacer member for maintaining the drum and the developing roller spaced from each other or the distance between centers of the drum and the developing roller to be larger than the distance therebetween during an image forming operation. The spacer member supports the first frame and second frame at least at longitudinally extending surfaces of the process cartridge, and is detachable from the process cartridge.