PURPOSE: To provide a clutch of a small size and a light weight, which can be manufactured easily, where abrasion in a sliding portion and noise are small in a clutch released state.

CONSTITUTION: Through holes 13 are formed on the circumferential wall of a cylindrical portion 12 disposed in a rotary base body 10 on a driving side. Hard balls 14 each having a diameter larger than a thickness of the circumferential wall are fitted into the through hole in a freely projected manner. A hard ball restricting portion 23, where recesses 23a for allowing the hard ball 14 to project toward the surface of the through hole and projections 23b for restricting the projection are alternately formed in the circumferential direction, is disposed on the inner surface of the circumferential wall of a cylinder 22 projected on one side of a rotary base body 20 on a driven side. A cam portion 31 having chevron-shaped projections 32, which is engaged with the hard balls 14 projected toward the back surfaces of the through holes so as to receive rotating force of the base body 10, is disposed on one side of an intermediate rotor 30, while driving projections 33 for transmitting the received rotating force to the base body 20 is disposed on the other side thereof. An elastic mechanism 40 for elastically receiving the rotating force is disposed in the base body. It is preferable that the through holes 13, hard balls 14, projections 32 of the cam portion, driving projections 33, and elastic members 44, 45 form a pair, respectively.