A cartridge mountable to and dismountable from a main assembly of an image forming apparatus includes a memory, a guide configured to guide a portion-to-be-guided provided in the main assembly and to guide a main assembly contact provided in the main assembly to a memory contact of the memory when the cartridge is mounted in the main assembly, and a grip portion. The guide is provided at a bottom of the cartridge when the cartridge is hung by gripping the grip portion and constitutes a part of a supporting portion configured to support the cartridge when the cartridge is placed on a horizontal placement surface. The guide has a chamfered surface formed by being chamfered. When the cartridge is supported at the supporting portion, the chamfered surface opposes the horizontal placement surface, and a surface of the memory contact is inclined with respect to the horizontal placement surface.