A brush driving mechanism, which drives a cleaning brush from a retracted position to an operation position opposed to a magnetic head, has a main arm having a tip coupled to the cleaning brush through a shaft. A chassis has a chassis slit, in which the shaft is inserted, for allowing to move the cleaning brush from the retracted position to the operation position by operating the main arm. The chassis slit has a tip portion stops the shaft when the cleaning brush is put into the operation position to position the cleaning brush with respect to the magnetic head.