Provided is a deep ultraviolet LED with a design wavelength λ, including a reflecting electrode layer, an ultra-thin metal layer, and a p-type contact layer that are arranged in this order from a side opposite to a substrate; and a hemispherical lens bonded to a rear surface of the substrate on a side of the p-type contact layer, the hemispherical lens being transparent to light with the wavelength λ. The refractive index of the hemispherical lens is greater than or equal to the average value of the refractive index of the substrate and the refractive index of air and is less than or equal to the refractive index of the substrate. The hemispherical lens has a radius that is greater than or equal to the radius of an inscribed circle of the substrate and is about equal to the radius of a circumscribed circle of the substrate.