A recliner has a ratchet and a guide assembled together so as to be rotatable relative to each other, and a pawl supported by the guide in its circumferential direction. The pawl has an outer tooth row adapted to mesh with a part of an inner tooth row of the ratchet so as to inhibit rotational movement of the ratchet relative to the guide. The outer tooth row of the pawl is meshed with the inner tooth row of the ratchet such that only two adjacent tooth flanks located in a center of the outer tooth row in the circumferential direction are in contact with the inner tooth row, and at least one of adjacent two tooth flanks of the outer tooth row located at positions other than the center in the circumferential direction is received in the inner tooth row without being in contact with the inner tooth row.