PURPOSE: To enable to conduct the Joule heat generated at a P-N junction to a heat sink member and at the same time to improve the heat dissipating effect caused by a micro uneven surface by a method wherein silicon is used as a submounting member, and many micro unevennesses are formed on the exposed surface around the junction of said member with a semiconductor laser element.

CONSTITUTION: A semiconductor laser element 2 is brazed to a submounting member 6 with a solder 3, and a heat sink member 4 is brazed to said member 6 with a solder 5. Many micro unnevennesses 7 are formed around the junction of said member 6 with said element. As the heat sink member 4, a metal excellent in thermal conductivity such as Cu and Ag is used, and Si is used as the submounting member 6. E.g. In, Sn, and In-Sn alloy is used for the solders 5 and 6.