A cartridge changer (41) is composed of a swing arm (48) with a cartridge gripper (48B) for gripping a paint cartridge (24), and an arcuate moving portion (46) for putting the swing arm (48) in swinging movements in a horizontal plane. The cartridge changer (41) is adapted to pick up a replenished paint cartridge (24) on the mount deck (42) by the cartridge gripper (48B) and transfer the swing arm (48) to a changing position “O” by the arcuate moving portion (46). By the operation, a used paint cartridge (24′) will be replaced by the replenished paint cartridge (24) between the mount deck (42) and a common body (15) which is located in the changing position “O” of the atomizing head changing and washing device (31).