A paint cartridge replenisher (51) is constituted by a replenishing stool (52) having a feed tube passage hole (56) and a container support portion (57), a connector member (59) connectable to and communicable with a fore distal end of a feed tube (28), and a replenishing valve (61) operative to turn on and off paint supply from a paint source to the connector member (59). A paint cartridge (25) is set on the container support portion (57), thereby passing the feed tube (28) into the feed tube passage hole (56) on the side of the replenishing stool and bringing a fore distal end portion of the feed tube (28) into fitting engagement with the connector member (59). In this state, the replenishing valve (61) is opened, whereupon paint is supplied from the paint source to the connector member (59) and replenished into the container (26) of the paint cartridge (25), utilizing the opening at the fore distal end of the feed tube as a replenishing port of the paint cartridge (25).