An air turbine drive spindle capable of suppressing a pressure increase inside a through hole is provided. A spindle includes a rotary shaft and an outer circumferential member (a housing assembly, a cover and a nozzle plate). The rotary shaft is provided with a through hole. The outer circumferential member includes a bearing sleeve configured to surround at least a portion of an outer circumferential surface of the rotary shaft. The outer circumferential member includes a gas supply portion and a gas exhaust hole. The spindle includes a second gas exhaust portion (a first gas exhaust hole and a first gas flow passage). The second gas exhaust portion is independent of the gas exhaust hole and continuous to outside from a gas exhaust space.