A rotary atomizing head (1) has an inner peripheral surface (2) expanded in diameter from the bottom (21) toward the front end of the rotary atomizing head (1) and also has at the bottom (21) a paint supply nozzle (11) for supplying paint (Lp) and cleaning liquid (Lw). Nozzle holes (10a) of the paint supply nozzle (11) are constructed to discharge the paint (Lp) and the cleaning liquid (Lw) in the direction substantially perpendicular to the rotation axis of the rotary atomizing head (1). Further, a dam (4) is provided on the inner peripheral surface (2) at its intermediate section located between the bottom (21) and a paint discharge end (2c), and the dam (4) dams the paint (Lp) and the cleaning liquid (Lw) that are supplied from the paint supply nozzle (11) to the bottom (21) and flow to the paint discharge end (2c) along the inner peripheral surface (2).