A reclining device of a vehicle seat including a ratchet, a guide, three pawls and a rotating cam. Three spacing distances are defined due to such positioning of the three pawls, and one of the spacing distances is determined so as to be greater than the remaining two spacing distances. A non-toothed raised flat portion is formed in a portion of an inner circumferential surface of an inner toothed portion of the ratchet at a single site in a circumferential direction thereof. The raised flat portion is protruded radially inwardly beyond tips of inner teeth. The smaller remaining two spacing distances are determined so as to be smaller than a circumferential length of the raised flat portion.