To provide a self-lock clutch capable of positively locking itself in a simple structure.

This self lock clutch includes a power transmission part 11 provided at the tip of a rotatively driving input shaft 1, and a swinging member 3 provided at the tip of an output shaft 2 forming a rotating axis L same as the input shaft 1 on the side of the input shaft 1 and pivoted around a swinging central axis SL eccentric from the rotating central axis L. The swinging member 3 has a structure capable of changing postures between a first posture where it is pressed with the power transmission part 11 based on the rotational drive of the input shaft 1, and a second posture for locking with a stationary member 4 provided in the radial direction of the swinging member 3 based on the rotational drive of the output shaft 2.