A semiconductor device with high reliability, low voltage, and high luminance is provided by preventing detachment of an electrode by way of obtaining good adhesion of the electrode, even in cases where a face-down mounting of a semiconductor laser is performed, and further, an insulating film and a protective film etc. are disposed in the area other than the area where the electrode is ohmically connected to the semiconductor layer. In a semiconductor device having an electrode electrically connected to the semiconductor layer, a dielectric film and an adhesion film comprising a degenerate semiconductor are stacked in sequence on a portion of a region between the semiconductor layer and the electrode, and the adhesion film is in contact with the electrode.