A semiconductor laser device which ensures high yield, high reliability and high power output by reduction in tensile strain in its active region for improvement in the COD level. The device comprises: a semiconductor crystal-growing portion having an active layer for conversion of electric energy into light energy and a mesa structure protruding on the one side; and an electrode film which is electrically connected with the top face of the mesa structure. The electrode film has a tensile strain and stretches sideward from the mesa structure. In the device, there is a strain control film which is polymerized with the electrode film part stretching sideward from the mesa structure and has a compressive stress.