PURPOSE: To obtain the title device, having a ring rotating unit constituted of a superconducting material and a magnet placed at a position of a ring fixing unit opposite the above-mentioned material and capable of readily rotating the ring rotating unit by action of an air stream without causing heat or noise even in high-speed rotation.

CONSTITUTION: The aimed device is constituted as follows. A rotating ring 1 is constituted of a superconducting material and a magnet is placed at a prescribed position of a ring fixing unit 2 so as to rotate the ring rotating unit 1 by an air stream blown from the ring fixing unit 2. Furthermore, the air stream is blown by, e.g., providing air holes 9 for blowing the air stream in the ring rotating unit 4 and blowing the air stream from the above-mentioned air holes 9 onto blades 6 of the ring rotating unit 1.