In a webbing take-up device, a structure for interlocking a second lock pawl with a first lock pawl is only a shaft. It also suffices for switching between restricting of rotation of a lock ring and cancelling of the restricting to be carried out merely by moving a piston by gas pressure generated at a gas generator. In this way, by a simple structure, it is possible to switch between a mode, in which torsional deformation is brought about at a sub torsion main body of a sub torsion shaft, and a mode, in which torsional deformation is not brought about at the sub torsion main body of the sub torsion shaft.