To provide a semiconductor laser used for various types of electronic equipment and a semiconductor wafer of its material and a method for manufacturing the wafer, and to enhance stability of the oscillation wavelength of the laser.

The semiconductor laser comprises an InGaAsP 13 as an active layer interposed between a p-type InP clad layer 12 and an n-type InP clad layer 14. In this case, a piezoelectric material 11 is adhered to the layer 12. With this constitution, a voltage applied between an AuZn 17 electrode and an Au 18 electrode is controlled to distort the material 11 and to apply a stress to the layer 13. The stability of the oscillation wavelength of the laser is enhanced by controlling the voltage applied to the piezoelectric material.