A nitride semiconductor ultraviolet light-emitting element comprising: a semiconductor laminated portion including an n-type layer composed of an n-type AIGaN-based semiconductor layer, an active layer of an AIGaN-based semiconductor layer formed on a first region on an upper surface of the n-type layer, and a p-type layer (23, 24, 25) composed of at least one p-type AIGaN-based semiconductor layer formed on an upper surface of the active layer; an n-electrode formed on a second region that is not the first region on the upper surface of the n-type layer; and a p-electrode formed on an upper surface of the p-type layer (23, 24, 25), wherein the active layer has a quantum well structure comprising at least one well layer composed of an AIGaN-based semiconductor layer, in the n-type layer below at least the first region of the upper surface of the n-type layer, a plurality of thin film-like Ga-rich layers that is a part of the n-type layer having a locally high Ga composition ratio exists spaced apart from each other in a vertical direction that is orthogonal to the upper surface, an extending direction of at least a part of the plurality of Ga-rich layers on a first plane parallel to the vertical direction is inclined with respect to an intersection line between the upper surface of the n-type layer and the first plane, in each of a plurality of second planes parallel to the upper surface of the n-type layer, the plurality of Ga-rich layers is present in stripes, and at least one of the plurality of second planes exists in an upper layer region having a thickness of 100nm or less at lower side from the upper surface of the n-type layer, and AlN molar fractions of the Ga-rich layers present below the first region are larger than an AlN molar fraction of the well layer, characterised in that a low impurity concentration layer having a relatively lower n-type impurity concentration than other regions in the n-type layer exists in the n-type layer as a layer parallel to the second plane, wherein the low impurity concentration layer is present in the upper layer region. a semiconductor laminated portion including an n-type layer composed of an n-type AIGaN-based semiconductor layer, an active layer of an AIGaN-based semiconductor layer formed on a first region on an upper surface of the n-type layer, and a p-type layer (23, 24, 25) composed of at least one p-type AIGaN-based semiconductor layer formed on an upper surface of the active layer; an n-electrode formed on a second region that is not the first region on the upper surface of the n-type layer; and a p-electrode formed on an upper surface of the p-type layer (23, 24, 25), wherein the active layer has a quantum well structure comprising at least one well layer composed of an AIGaN-based semiconductor layer, in the n-type layer below at least the first region of the upper surface of the n-type layer, a plurality of thin film-like Ga-rich layers that is a part of the n-type layer having a locally high Ga composition ratio exists spaced apart from each other in a vertical direction that is orthogonal to the upper surface, an extending direction of at least a part of the plurality of Ga-rich layers on a first plane parallel to the vertical direction is inclined with respect to an intersection line between the upper surface of the n-type layer and the first plane, in each of a plurality of second planes parallel to the upper surface of the n-type layer, the plurality of Ga-rich layers is present in stripes, and at least one of the plurality of second planes exists in an upper layer region having a thickness of 100nm or less at lower side from the upper surface of the n-type layer, and AlN molar fractions of the Ga-rich layers present below the first region are larger than an AlN molar fraction of the well layer, characterised in that a low impurity concentration layer having a relatively lower n-type impurity concentration than other regions in the n-type layer exists in the n-type layer as a layer parallel to the second plane, wherein the low impurity concentration layer is present in the upper layer region.