According to the present invention, in a semiconductor laser device (10) having different facet reflectivities, an electrode disposed on a stripe ridge (107a) is divided into four electrode parts (1), (2), (3), and (4), and a larger injection current is injected to an electrode part that is closer to a light emission facet side. According to this semiconductor laser device, a carrier density distribution in an active layer that is opposed to the stripe ridge can be matched to a light intensity distribution in the active layer, thereby preventing degradation in high output characteristic due to destabilization of transverse mode and reduction in gain which are caused by spatial hole burning.