There is provided a semiconductor light emitting device including: a first conductivity-type semiconductor base layer; a mask layer disposed on the first conductivity-type semiconductor base layer and including a graphene layer with a plurality of openings exposing the first conductivity-type semiconductor base layer; and a plurality of light emitting nanostructures disposed on the openings and each including a first conductivity-type semiconductor core, an active layer, and a second conductivity-type semiconductor layer.