A tape library wherein a number of cassette tapes are accommodated and adjusted. One or more expansion units are connected to a basic unit. When a transport mechanism is within the basic unit, a control circuit section controls the transport mechanism by referencing a position reference point of the basic unit, and when the transport mechanism is within an expansion unit the control circuit section controls referencing a position reference point of the expansion unit. The control circuit section and the transport mechanism of the basic unit are interconnected by an elongated-belt-like flat cable which includes a plurality of conductors extending in parallel and joined with an insulating material, and when an expansion unit is coupled the cable need not be replaced, allowing coupling of an expansion unit and smooth transportation of a recording medium in the expansion unit to a recording and/or playback section by the transport mechanism.