Abstract: A process cartridge integrally supports an electrophotographic photosensitive member, an intermediate transfer belt, primary transferer for transferring a toner image primarily from the member to the belt, a charge provider for providing the toner on the belt with electric charges having a polarity reverse to the polarity the toner has at the time of the primary transfer and returning the toner on the belt to the member at a contact zone to clean the belt, and an electrophotographic-photosensitive-member cleaner. The cartridge is dividable into an electrophotographic photosensitive member unit and an intermediate transfer belt unit and has a joining unit which joins the two units. The peripheral length and average thickness of the belt and the diameter of at least one of rollers over and around which the belt is placed satisfy specific conditions.