A light-emitting device having a plurality of light-emitting elements closely adjacently disposed in spite of using only one substrate is provided.One or more light-emitting elements are flip-chip mounted on each of upper surface and lower surface of a substrate. The light-emitting elements are disposed so that the light-emitting elements on the upper surface of the substrate and the light-emitting elements on the lower surface of the substrate are closely adjacent to each other when they are seen from above the substrate. The light-emitting elements mounted on the upper surface of the substrate have light-emitting surfaces as the upper surfaces, and the light-emitting elements mounted on the lower surfaces of the substrate have light-emitting surfaces on the substrate side. The substrate transmits at least lights emitted by the light-emitting elements mounted on the lower surface of the substrate.