A semiconductor light-emitting device including an insulating film, an optical resonator formed on the insulating film, and a p-electrode and an n-electrode which are disposed on the both sides of the optical resonator, respectively. The optical resonator includes a first semiconductor wire and a second semiconductor wire which are arranged in parallel with a space left therebetween, the space being narrower than emission wavelength, resonator mirrors disposed at the both ends of these semiconductor wires, and a plurality of semiconductor ultra-thin films which are interposed between the first semiconductor wire and the second semiconductor wire and are electrically connected with these semiconductor wires, the first semiconductor wire is electrically connected with the p-electrode, and the second semiconductor wire is electrically connected with the n-electrode, thereby enabling the semiconductor ultra-thin films to generate laser oscillation as a current is injected thereinto.