Résumé dans la langue de publication When it is desired to change a cartridge (25) with respect to a painting device (11), this is done by removing a filled cartridge (25) of next color from a paint filling device (55a-55n) by one gripper (101) of a cartridge gripping device (100). With the filled cartridge (25) held by one gripper (101), a used cartridge (25) is gripped and removed from the painting device (11) by the other gripper (102). Further, the filled cartridge (25) held by one gripper (101) is attached to the painting device (11) and the empty cartridge (25) is returned to the paint filling device (55a-55n) by the other gripper (102). This makes it possible to simplify the changing operation of cartridges (25).