Résumé dans la langue de publication A washing fluid is supplied from the front surface of a rotary atomization head (28) by using a washing nozzle (14) to wash the head (28). A coating machine (20) is so mounted to a coating robot (1) as to be capable of moving in an arbitrary direction and a washing machine (10) for an atomization head is disposed in the proximity of the coating robot (1). The coating robot (1) is operated at the time of washing and the rotary atomization head (28) of the coating machine (20) is inserted into a waste liquid recovery container (13) of the washing machine (10) for the atomization head. A thinner is discharged from a washing nozzle (14) under this state and is supplied to the front surface of a hub member (30) constituting the rotary atomization head (28). The thinner flows from a solvent outflow port (30C) formed in the hub member (30) into the rotary atomization head (28) and washes away the paint adhering to the rotary atomization head (28).