Abstract: There is provided a seat belt apparatus which not only can reduce the possibility that an end lock phenomenon can occur when removing the mounting of a webbing but also, even in case where the end lock phenomenon occurs, can remove the end lock phenomenon easily. That is, in a seat belt apparatus including a seat belt retractor having a lock mechanism structured such that, when the acceleration of a vehicle body or the pay-out acceleration of a webbing is a predetermined value or more, a pawl member (15) is engaged with a pawl wheel (13) to lock the rotation of a bobbin (2) with the webbing wound thereon in the webbing pay-out direction, the pawl wheel (13) is structured such that two or more kinds of ratchet teeth (T1) and (T2) differing in addendum circle diameter are mixedly arranged in the peripheral direction of the pawl wheel according to a predetermined manner, thereby being able to lower the probability of the webbing end lock occurring.