To enable to carry out color changing simply.

When a coating material cartridge 40 is supported on a supporting table 10 for coating and air couplers 16 and 48 are connected to each other, an air opening and closing valve 17 is opened to supply air to an air chamber 42 and a coating material in a coating material chamber 43 is forcibly sent to a coating gun 63. When the coating material cartridge 40 is supported on a supporting table 30 for replenishing and coating material couplers 36 and 51 are connected to each other, a coating material stop valve 53 is opened to replenish the coating material to the coating material chamber 43. The color changing is performed only by moving the coating material cartridge 40 between the supporting table 10 for coating and the supporting table 30 for replenishing and then, the time and labor are saved and excellent workability is attained.