A drum cartridge includes: a drum frame to which a developing cartridge is attachable; a photosensitive drum; and a first storage medium. The drum frame has one end portion and another end portion spaced apart from the one end portion in a first direction. The photosensitive drum is rotatable about a first axis extending in a second direction and is positioned at the one end portion of the drum cartridge. The first storage medium includes a first electrical contact surface. The first storage medium is positioned at an outer surface of the drum frame, the outer surface being exposed in a state where the developing cartridge is attached to the drum frame.