To provide a low-cost torque transmission device which can be restored to a torque transmission status after step-out and a switch device using this.

A driving side rotator 2 has permanent magnets 21 positioned with an equal interval between each other along the circumferential direction so that the polarities alternate each other. A follow-moving side rotator 1 has salients 11 positioned with an equal interval between each other along the circumferential direction so that they face against each of the permanent magnets 21. The salients 11 are surrounded by non-magnetic conductors 3. Since the non-magnetic conductors 3 surround the salients 11, according to the law of Lenz, an induction current is generated by the magnetic flux of the permanent magnets 21. Therefore, because of the effect of the magnetic field due to this induction current, a repulsion force and a suction force work between each of the magnets 21 and each of the salients 11 in order to prevent the driving side rotator 2 from slipping so that a torque is transmitted from the driving side rotator 2 to the follow-moving side rotator 1.