To provide a dental hand piece of an air turbine type in which the wear of balls and a retainer in a ball bearing is prevented as much as possible and of which the increase of the manufacture cost is suppressed.

The dental hand piece is provided with a bar sleeve 13 receiving a dental treating tool, a rotor 16 provided on the bar sleeve so as to rotationally drive the bar sleeve by supplied compressed air, and the ball bearings 14 and 15 provided on the upper part and lower part of the rotor so as to rotatably support the bar sleeve. For the ball bearings at the upper and lower parts, ceramic balls 14c and 15c are used without providing the retainer.