A nondrive-side side member forms a part of a cartridge and includes a frame portion, and a regulation frame portion provided in the frame portion, to regulate movement of the cartridge. The frame portion has a hole provided to expose an electric contact. Further, a drive-side side member forms a part of a cartridge and includes a frame portion having a first hole and a second hole with a diameter larger than a diameter of the first hole, and a slit portion into which a memory for storing information is to be inserted.