A semiconductor light-emitting device includes a first conductivity-type semiconductor including a first electrode on a first main surface, a second conductivity-type semiconductor, and an active layer between a second main surface of the first conductivity-type semiconductor and a first main surface of the second conductivity-type semiconductor. Protrusions are disposed in at least part of a region of a second main surface of the second conductivity-type semiconductor facing the first electrode. A second electrode is disposed in at least part of a region of the second main surface of the second conductivity-type semiconductor except the region having the protrusions. The protrusions containing a dielectric material protrude from the second main surface of the second conductivity-type semiconductor in a direction away from the active layer and are separated by intervals longer than the wavelength of light emitted from the active layer in the medium of the protrusions.