A nitride semiconductor laser chip 103 is fixed to a submount 102 serving
as a mount member with solder 107. The submount 102 is made of a
material having a thermal expansion coefficient higher than that of a nitride semiconductor
substrate, and has a thickness equal to or greater than 1.2 times the thickness
of the layered nitride semiconductor structure composed of an n-type GaN substrate
1 and a layered nitride semiconductor portion 2. Between the n-type
GaN substrate 1 and the submount 102 is laid a metal film having
a thickness of from 1 to 50 m.
