Abstract: An air turbine drive spindle includes a rotary shaft, a bearing portion, a damper ring, a cover member, and at least one or more O rings. The bearing portion surrounds at least a portion of an outer circumferential surface of the rotary shaft. The damper ring is disposed at the outer circumferential side relative to the bearing portion with a gap being interposed therebetween. The cover member is disposed at the outer circumference side relative to the damper ring with a gap being interposed therebetween, and is configured to store the rotary shaft, the bearing portion, and the damper ring. At least one or more O rings are disposed in each of the gap and the gap.