LOCKING TOOL

A locking tool includes an igniter, a cup-shaped member, a holder and a weak portion. The cup-shaped member includes a cylindrical portion fitted into a tip portion of the igniter, a bottom portion positioned on a side of the tip portion of the igniter, and an actuation pin that is formed outside the bottom portion and configured to lock an object. The holder holds the igniter and the cup-shaped member. The weak portion is formed at a position facing an outer peripheral portion of the actuation pin inside the bottom portion of the cup-shaped member.