A toner cartridge (20) has a shutter (40) adapted to be changed between a closed posture (S1) and an open posture (S1) for opening a toner supply port (322), a lever (50) to be operated manually to change the posture of the shutter (40), and a postural-change restriction mechanism (60) for controlling a postural change of the shutter (40). The postural-change restriction mechanism (60) includes a lock groove (53) in the lever (50), and a restriction pawl (62) integrally formed with a cartridge body (30). The restriction pawl (62) engages the lock groove (53) when the lever (50) is operated to set the shutter (40) in the closed posture (S1), to block a postural change of the shutter (40), and to be elastically deformed when the cartridge body (30) is attached to a development device, in a manner to allow the postural change.