Group III nitride semiconductor light-emitting device

bbaammmIn a Group III nitride semiconductor light-emitting device which includes a substrate and a light-emitting layer having a multiple quantum well structure including a barrier layer, which is provided on a surface of the substrate and formed of a Group III nitride semiconductor, and a well layer formed of an indium-containing Group III nitride semiconductor, the light-emitting layer is constituted by stacking a plurality of multilayer portions which have one unit multilayer portion including the well layer and the barrier layer or two or more stacked unit multilayer portions. When the multilayer portion includes two or more unit multilayer portions, the respective well or barrier layers have the same thickness and composition, and in the respective multilayer portions, the barrier layers of the unit multilayer portions are different in thickness with respect to one another.