An annular gap space (18), into which a part of turbine air for driving a turbine (6) and exhaust air discharged from a rear thrust air bearing (12) flow out, is provided between an inner peripheral surface (5B) of a rotational shaft (5) and an outer peripheral surface (17B) of a feed tube (17). Air outflow holes (25) are provided in the rotational shaft (5) to be positioned between a radial air bearing (8) and a rotary atomizing head (16) and to be radially bored through the rotational shaft (5). As a result, the exhaust air flowing in the annular gap space (18) flows out outside of the rotational shaft (5) from the air outflow holes (25) in a position behind the rotary atomizing head (16).