A method of manufacture for a nitride semiconductor light emitting element, the nitride semiconductor light emitting element comprising: a monocrystalline substrate; an AlN layer provided on a surface of the monocrystalline substrate; a first nitride semiconductor layer of a first electrical conductivity type provided on the AlN layer; a light emitting layer made of an AlGaN-based material and provided on an opposite side of the first nitride semiconductor layer from the AlN layer; and a second nitride semiconductor layer of a second electrical conductivity type provided on an opposite side of the light emitting layer from the first nitride semiconductor layer, and the method comprising a step of forming the AlN layer on the monocrystalline substrate prepared and set in a reactor, wherein the step comprising: a first step of supplying an A1 source gas and a N source gas into the reactor to generate a group of AlN crystal nuclei having Al-polarity to be a part of the AlN layer on the surface of the monocrystalline substrate; a second step of supplying the A1 source gas and the N source gas into the reactor to form the AlN layer on the surface of the monocrystalline substrate, after the first step; and a third step of increasing a size of the AlN crystal nucleus generated through the first step between the first step and the second step, wherein in the first step, a substrate temperature, which is a temperature of the monocrystalline substrate, is selected to be a first predetermined temperature where growth of AlN crystals having N-polarity is suppressed, and in the third step, the A1 source gas and the N source gas are supplied to increase the size of the A1N crystal nucleus and the substrate temperature is selected to be a second predetermined temperature higher than the first predetermined temperature. a monocrystalline substrate; an AlN layer provided on a surface of the monocrystalline substrate; a first nitride semiconductor layer of a first electrical conductivity type provided on the AlN layer; a light emitting layer made of an AlGaN-based material and provided on an opposite side of the first nitride semiconductor layer from the AlN layer; and a second nitride semiconductor layer of a second electrical conductivity type provided on an opposite side of the light emitting layer from the first nitride semiconductor layer, and a first step of supplying an A1 source gas and a N source gas into the reactor to generate a group of AlN crystal nuclei having Al-polarity to be a part of the AlN layer on the surface of the monocrystalline substrate; a second step of supplying the A1 source gas and the N source gas into the reactor to form the AlN layer on the surface of the monocrystalline substrate, after the first step; and a third step of increasing a size of the AlN crystal nucleus generated through the first step between the first step and the second step, wherein in the first step, a substrate temperature, which is a temperature of the monocrystalline substrate, is selected to be a first predetermined temperature where growth of AlN crystals having N-polarity is suppressed, and in the third step, the A1 source gas and the N source gas are supplied to increase the size of the A1N crystal nucleus and the substrate temperature is selected to be a second predetermined temperature higher than the first predetermined temperature.