A process cartridge for use in an electrophotographic image forming apparatus. The process cartridge includes an electrophotographic photosensitive drum having a photosensitive layer at a peripheral surface thereof, with the electrophotographic photosensitive drum being rotatable about an axis thereof. The process cartridge also includes a coupling member to receive a rotational force for rotating the electrophotographic photosensitive drum, with the coupling member capable of taking a rotational force transmitting angular position for transmitting the rotational force to the electrophotographic photosensitive drum. The coupling member is also capable of taking a disengaging angular position in which the coupling member is inclined away from the rotational force transmitting angular position.