A refrigerator includes a main body having a storage chamber; a shelf movably provided to the inside of the storage chamber; a guide unit guiding a movement of the shelf; and a transfer means provided at least one side of the shelf and transferring driving power for moving the shelf. The valve sealing body is operable between open and closed positions which allow for fluid-flow and non-flow, respectively. The information processing apparatus includes copying means for, when the storage medium is attached thereto, copying a program stored in the storage medium thereinto in the case where the main body ID has not yet been registered. This operation is supported by a guide plate, which combs with the clamping rings. The outer surface of the clutch assembly housing is fixedly attached to the inner surface of the outer wheel.