A retaining apparatus for a data storage device includes a tray, a gasket and a fastener. The drive assembly has a pinion with at least two slots that receive axially extending protrusions of a barrel element. And the thin film of microporous silica which made chiefly of silicon has high heat-resistant properties similarly to the optical fiber itself. The capacitor slows down the speed of change of applied voltage to the solenoid from the rated voltage to the holding voltage so that the back electromotive force of the solenoid is absorbed, which prevents the extinguishment of magnetic flux density. The shutter is, prior to mounting the powder container to the apparatus, in a closed location to block the opening and, when the powder container is mounted, is moved along an outer peripheral surface of the body to an opened location to open the opening. The excess flow shut off device is easy in quality management and allows an easy manufacture of uniform products operating under the same conditions because a support member, a spring, an opening and closing member, a joining member, and a cylindrical member are integrally joined together and modulated.