A cartridge includes a projection portion provided in a first region of an upper surface of a frame in a vertical direction. The projection portion projects more upward than second regions between which the first region is interposed. An inside of the projection portion is a space that is part of a developer accommodating portion. The projection portion is configured to pass through a space under an abutting portion while being elastically deformed by the abutted portion being pressed by the abutting portion after the cartridge is transitioned from the first posture to the second posture in accordance with movement of the cartridge in the attaching direction.