An optical head in which a plurality of semiconductor laser chips are adhered on a mount surface perpendicular to the tracking servo direction of a focusing lens. Fluctuation of an optical spot power is reduced even if the tracking servo is performed by the optical head having dispersion of an inner surface direction when a plurality of the semiconductor laser chips are mounted. In FIG. 1, a plurality of the semiconductor laser chips 4a and 4b are arranged so as to have a mounting direction which is substantially perpendicular to the tracking servo direction of the focusing lens.