A process cartridge includes a casing, a photosensitive drum having an axis L1, and a drum flange provided at an end of the photosensitive drum. The process cartridge also includes a coupling member having an axis L2, with the coupling member including (i) a first end portion at least a part of which is positioned within the drum flange, and (ii) a second end portion including (ii-i) a surface recessed in the second end portion and facing away from the first end portion and (ii-ii) at least one projection projecting from a surface adjacent to the recessed surface, and (iii) a connecting portion connecting the first end portion and the second end portion.