In this buckle device, a base end portion of a belt is folded back on itself to form a ring-shaped portion, and the belt is wound onto a spool in a state in which the ring-shaped portion of the belt has been inserted through an insertion hole in the spool. This enables a winding radius of the belt to be increased by the base end portion of the belt and enables a load at which the belt is permitted to be pulled out to be reduced, when the belt is pulled out from the spool.