A portable hard disc device which is read by a recording and/or reproducing apparatus, including: a disc for recording and/or reproducing; a head slider for recording and/or reproducing the disc; an arm mechanism for moving the head slider to a predetermined position; a voice coil motor type coil for driving the arm mechanism by being driven by an external magnetic field generated by magnets provided in the recording and/or reproducing apparatus and a current supplied from a power circuit; a spindle for rotating the disc after the disc is fixed; and a power circuit for supplying a current to the voice coil motor type coil.