Résumé dans la langue de publication A coating method capable of applying paints of many colors interchangeably by providing detachably a paint cartridge (35) for each color to a rotary atomizing head type coating device (21) used for the painting method, comparing a paint cartridge attaching step for attaching the paint cartridge (35) to a housing (22), a painting step for supplying paint in the cartridge (35) to a rotary atomizing head (30), a paint cartridge removing step for removing a used cartridge (35) from the housing (22), and a cleaning step for supplying a cleaning liquid to the front of the atomizing head (30) by means of an atomizing head cleaning device (57) and cleaning the previous color paint attached to the head (30). Therefore, the next color paint can be applied by simply changing, after cleaning the head (30) from the front side thereof, a paint cartridge (35) when a paint color is to be changed.