A vertical ultraviolet light-emitting diode having an emission peak wavelength in a range of 210 to 300 nm, wherein the ultraviolet light-emitting diode comprises an n-type AIN single crystal substrate and has, on an aluminum polar plane of said n-type AIN single crystal substrate, a layer represented by n-type Al X Ga 1-X N (wherein X is a rational number satisfying 0.5≤X≤1.0), an active layer, a layer represented by p-type Al Y Ga 1-Y N (wherein Y is a rational number satisfying 0.5≤Y≤1.0) and a p-type GaN layer in this order, the ultraviolet light-emitting diode is equipped with a p-electrode formed on the p-type GaN layer and an n-electrode of an n-type ohmic electrode material formed on a plane on the opposite side to the aluminum polar plane of the n-type AIN single crystal substrate, the n-electrode being provided with at least one opening functioning as a light extraction window, the shortest distance between an edge of the n-electrode and an arbitrary point in the opening is not more than 400 μm, in a portion where the n-electrode is formed on the n-type AIN single crystal substrate, a thickness of a damage layer at the portion from the n-type AIN single crystal substrate surface is not more than 50 nm, wherein the damage layer is defined as a layer in which fluctuation or dislocation of the crystal structure occurs, and wherein the presence of the damage layer can be confirmed by contrast difference in the image of a transmission electron microscope of 100000 to 1000000 magnifications, a specific resistance of the n-type AIN single crystal substrate is not more than 300 Ω·cm, and a thickness of the n-type AIN single crystal substrate is 50 to 500 μm. the ultraviolet light-emitting diode comprises an n-type AIN single crystal substrate and has, on an aluminum polar plane of said n-type AIN single crystal substrate, a layer represented by n-type Al X Ga 1-X N (wherein X is a rational number satisfying 0.5≤X≤1.0), an active layer, a layer represented by p-type Al Y Ga 1-Y N (wherein Y is a rational number satisfying 0.5≤Y≤1.0) and a p-type GaN layer in this order, the ultraviolet light-emitting diode is equipped with a p-electrode formed on the p-type GaN layer and an n-electrode of an n-type ohmic electrode material formed on a plane on the opposite side to the aluminum polar plane of the n-type AIN single crystal substrate, the n-electrode being provided with at least one opening functioning as a light extraction window, the shortest distance between an edge of the n-electrode and an arbitrary point in the opening is not more than 400 μm, in a portion where the n-electrode is formed on the n-type AIN single crystal substrate, a thickness of a damage layer at the portion from the n-type AIN single crystal substrate surface is not more than 50 nm, wherein the damage layer is defined as a layer in which fluctuation or dislocation of the crystal structure occurs, and wherein the presence of the damage layer can be confirmed by contrast difference in the image of a transmission electron microscope of 100000 to 1000000 magnifications, a specific resistance of the n-type AIN single crystal substrate is not more than 300 Ω·cm, and a thickness of the n-type AIN single crystal substrate is 50 to 500 μm.