Abstract: A nitride-based semiconductor light-emitting device according to the present invention has a nitride-based semiconductor multilayer structure 50. The nitride-based semiconductor multilayer structure 50 includes: an active layer 32 including an AlaInbGacN crystal layer (where a+b+c=1, a?0, b?0 and c?0); an AldGaeN overflow suppressing layer 36 (where d+e=1, d>0, and e?0); and an AlfGagN layer 38 (where f+g=1, f?0, g?0 and f<d). The AldGaeN overflow suppressing layer 36 is arranged between the active layer 32 and the AlfGagN layer 38. And the AldGaeN overflow suppressing layer 36 includes an In-doped layer that is doped with In at a concentration of 1×1016 atms/cm3 to 1×1019 atms/cm3.