Damage of a connection between a connector and a circuit board on which the connector is mounted is to be prevented at the time of connecting the connector with a corresponding connector on a host side. In one embodiment, an HDD is provided with a serial ATA connector. The connector is mounted on a circuit board. The HDD is also provided with stiffeners for fixing the connector to the circuit board. When the connector moves toward a base at the time of connection thereof to a host-side connector, the stiffeners come into abutment against the base to stop the movement of the connector. As a result, damage of the connection between the connector and the circuit board can be prevented.