A lighting device may be provided that includes: a heat sink which includes a base and a projection extending from the base and having one side; a light source which includes a substrate disposed on the one side of the projection and a light emitting device disposed on the substrate; an optical plate disposed on the light emitting device; a driving part which is disposed on the base and is electrically connected to the light source; and a housing which receives the heat sink, the light source, the optical plate and the driving part, wherein the one side of the projection is disposed between a first point and a second point, wherein the first point indicates a half of the overall height of the housing, and wherein the second point indicates a minimum interval of 5 mm between the light emitting device and the optical plate.