Provided is a developer cartridge attachable to and detachable from a main body of an image forming apparatus. The developer cartridge includes: a memory unit including a contact portion moved to a first position hidden inside the developer cartridge and a second position protruding outside the developer cartridge; an operating portion configured to move the contact portion to the first position and the second position; an outlet configured to discharge a developer; and a first shutter having an opening position and a closing position for opening and closing the outlet and moved to the closing position and the opening position when the contact portion is moved to the first position and the second position.