A developing body includes: an excluding portion including a movable wire and fixing wires arranged around the movable wire, a distal end of the movable wire and distal ends of the fixing wires being connected to each other； an insertion tube allowing the movable wire to pass therethrough； and a restriction member that is connected to a proximal end of the movable wire. The restriction member restricts the movement of the movable wire when the restriction member abuts against the first grip portion. When the first grip portion and the second grip portion are moved relative to each other so as to be close to each other in this state, the excluding portion is developed by bringing the distal end of the insertion tube and the distal end of the movable wire to be close to each other to deflect the fixing wire.
