Removably to the main assembly mountable process cartridge of an electrophotographic image forming apparatus includes a developing member for developing the charging member and the latent image formed on the photosensitive drum to the electrical charges the electrophotographic photosensitive drum, a photosensitive drum, a process cartridge main a grounding post the photosensitive drum to the main assembly when it is mounted on the assembly and a ground contact having a contact surface for coupling with a corresponding contact of the main assembly and a process developing bias applied to the developing member when the cartridge is mounted to the main assembly from the main assembly a developing bias contact for receiving, and a cartridge coupling member for receiving a charging bias contact for receiving a charging bias applied to the charging member when the process cartridge is mounted to the main assembly from the main assembly, a driving force for rotating the photosensitive drum from the main assembly including Joe, and the process cartridge weeks When it is mounted on the body is engaged with the main assembly coupling member, the cartridge coupling member is coupled to the main assembly coupling member and the shaft, and the cartridge coupling member is disposed to the photosensitive drum and the shaft from the one longitudinal end of the photosensitive drum, grounding contacts cartridge is disposed at a the other end of the drum portion opposite from the coupling member is arranged lengthwise end, a developing process, which faces downward when the bias contact and charging bias contact is disposed adjacent to the other longitudinal end, each process cartridge is mounted to the main assembly of the cartridge is provided on the side of the contact surface of the ground contacts are arranged in coaxial with the photosensitive drum.