PURPOSE: To form a thin current constriction layer regardless of the conductive type of a substrate by using the Ga1-xAlxAs which has increased in resistance been made the resistance higher as a current constriction layer.

CONSTITUTION: A semiconductor substrate 20 is formed by laminating a non- doped GaAs layer 22. A Ga1-xAlxAs layer 23, and a non-doped GaAs layer 24 on an N-type GaAs substrate 21 by organic metal chemical vapor deposition technique. A groove 25 is formed on the semiconductor substrate 20 and N-type GaAlAs cladding layer 26, a P-type GaAlAs active layer 27, a P-type GaAlAs cladding layer 28, and a P-type GaAs cap layer 29 are laminated by liquid-phase growth technique. After thus forming an electrode, that is separated into elements to obtain the semiconductor laser element 30 comprising a high- resistance GaAlAs layer 23 as a current constriction layer on the N-type GaAs substrate 21.