A semiconductor light emitting device includes a light emitting structure including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, a first electrode disposed below the light emitting structure, the first electrode being electrically connected to the first conductivity type semiconductor layer, a second electrode within the light emitting structure, the second electrode being electrically connected to the second conductivity type semiconductor layer, an insulating part electrically separating the second electrode from the first conductivity type semiconductor layer, the active layer, and the first electrode, a first pad electrode electrically connected to the first electrode, and a second pad electrode electrically connected to the second electrode, the second pad electrode being exposed to a top surface of the light emitting structure.