Webbing take-up device

A webbing take-up device is disclosed which includes a take-up shaft onto which a webbing is mound, and a mounting member nondetachably mounted to the take-up shaft by screw tightening. The take-up shaft and the mounting member are engaged with each other at a portion other than a portion where the screw tightening is carried out, thereby preventing relative rotation of the take-up shaft and the mounting member.