A process cartridge includes an electrophotographic photosensitive drum and a frame for supporting the electrophotographic photosensitive drum. The process cartridge also includes a first portion-to-be-positioned for being positioned to a first main assembly side positioning portion provided in the main assembly of an apparatus, a second portion-to-be-positioned for being positioned to a second main assembly side positioning portion provided in the main assembly of the apparatus, and a longitudinal positioning portion to be positioned by a main assembly side longitudinal positioning portion provided in the main assembly of the apparatus. The apparatus still further includes a portion-to-be-urged for receiving an inclined downward elastic force of a first main assembly side elastic member provided in the main assembly of the apparatus to urge the longitudinal positioning portion and the second portion-to-be-positioned.