In a semiconductor laser, a laminated multi-layer body is on a prescribed region of the surface of a semiconductor substrate of first conductivity type, and a burying laminated layer body surrounds the laminated layer body in contact with the lateral wall thereof. The laminated layer body includes a first cladding layer having the first conductivity type, a first active layer, a second cladding layer having the opposite conductivity type (second conductivity type) to that of the semiconductor substrate, a second active layer and a third cladding layer of the first conductivity type. The burying laminated layer body includes a semiconductor electrode layer of the second conductivity type and low specific resistivity which substantially contacts the second cladding layer, and two groups of burying layers respectively provided on the prescribed regions of the top and bottom surface of said semiconductor electrode layer. When a prescribed amount of direct current is supplied to a first electrode mounted on the upper side of the laminated layer body, a second electrode deposited on the bottom side of said laminated layer body and a third electrode set on the semiconductor electrode layer included in the burying layer body, then the first and second active layers arranged very close to each other simultaneously oscillate two independent laser beams admitting of modulation with a low threshold current value.