Résumé dans la langue de publication A cartridge (35) of each of the colors is detachably attached to a coating device (21) so that the coating materials of many colors can be applied by being changed one by one without discharging the coating materials. The cartridge (35) of each of the colors is changeably attached to the housing (22). The cartridge (35) is further provided with a coating valve (46) which provides communication and cutoff of a thinner valve (54) which provides communication and cutoff of a coating material feed passage (39A) in a feed tube (39). Either the housing (22) or the cartridge (35) is provided with a thinner passage (48) on the side of the housing. Thus, the single coating device (21) copes with the operation for changing many colors. The costing material valve (46) and the thinner valve (54) are opened and closed by a coating material spray instruction and a stop instruction, therefore, immediately after the instruction, the spray of coating material is started or stopped.