A semiconductor light emitting device includes a plurality of light emitting cells having first and second surface opposing each other, the plurality of light emitting cells including a first conductivity-type semiconductor layer, a second conductivity-type semiconductor layer, and an active layer therebetween, an insulating layer on the second surface of the plurality of light emitting cells and having first and second openings defining a first contact region of the first conductivity-type semiconductor layer and a second contact region of the second conductivity-type semiconductor layer, respectively, a connection electrode on the insulating layer and connecting a first contact region and a second contact region of adjacent light emitting cells, a transparent support substrate on the first surface of the plurality of light emitting cells, and a transparent bonding layer between the plurality of light emitting cells and the transparent support substrate.