A laser driver is configured so as to disperse into a main circuit which generates a control signal to drive first and second semiconductor lasers, and first and second sub circuits having first and second final driving stages which drive, in accordance with the control signal, the first and second semiconductor lasers, respectively, and the main circuit comprises a selection circuit which selectively supplies the control signal to the sub circuits to be operated in conformity with the kind of recording medium, and the first sub circuit is placed closer to a connection area to the first semiconductor laser of a flexible circuit board than the main circuit or placed on this connection area; and the second sub circuit is placed closer to a connection area to the second semiconductor laser of the flexible circuit board than the main circuit or placed on this connection area.