A rotating device comprises: a hub on which a magnetic recording disk is to be mounted; a base configured to rotatably support the hub via a bearing; a shaft configured such that it extends along the rotational axis of the hub; and a chassis arranged such that it faces the magnetic recording disk, and configured to have a Young's modulus that is smaller than that of the base. A base hole is provided to the upper face of the chassis that faces the magnetic recording disk such that it extends along the rotational axis. Furthermore, the base is fitted into the base hole, thereby fixedly mounting the base on the chassis.