A semiconductor light-emitting device includes: a first semiconductor layer; a light-emitting layer being disposed on the first semiconductor layer; a second semiconductor layer being disposed on the light-emitting layer, and metal electrodes connected to the first semiconductor layer and the second semiconductor layer. The light-emitting layer is lower in refractive index than the first semiconductor layer. The second semiconductor layer is lower in refractive index than the light-emitting layer. The metal electrodes supply a current to the light-emitting layer.