PURPOSE: To wash automatically the paint sticking in a painting nozzle by ejecting the washing liquid for the paint to be forcibly fed by a pump from a washing nozzle pierced to an annular pipe, thereby washing the paint sticking in the nozzle of the paint gun.

CONSTITUTION: The body and nozzle 3 of a painting gun 7 are operated by an arm 8 to stop perpendicularly in the upper part in a washing tank 9, and the tip of the nozzle 3 of the gun 7 is directed downward in the stage of washing the nozzle 3 of the gun 7. A washing nozzle 12 pierced with small holes directing upward obliquely around the upper side of an annular pipe 10 apart by a downward space from the tip of the nozzle 3 in the tank 9 and is provided and is communicated and supported with and by a curved pipe 13 communicating with said pipe 10. Said nozzle is connected to the pipe 13 by means of a piping 15 communicating with a discharging port for a thinner or the like of a pump 14.