There are provided a semiconductor light emitting device and a method of manufacturing the same. A method of manufacturing a plurality of light emitting nanostructures of a semiconductor light emitting device includes: forming a plurality of first conductivity type semiconductor cores on a first type semiconductor seed layer, each first conductivity type semiconductor core formed through an opening in an insulating film; forming an active layer on each first conductivity type semiconductor core; forming, using a mask pattern, a second conductivity type semiconductor layer on each active layer to cover the active layer, to form a plurality of light emitting nanostructures; and forming an electrode on the plurality of light emitting nanostructures.