A lighting device comprising: a heat sink having an optical transmittance; a light source module including a substrate disposed on the heat sink and a light emitting device disposed on the substrate; and a cover (100, 100') which is disposed on the light source module and outwardly emits a part of light from the light source module, wherein the cover (100, 100') has an inner surface which reflects a part of light from the light emitting device, and wherein the heat sink receives the light from the inner surface of the cover (100, 100') and outwardly emits a part of the received light, Characterized in that the heat sink comprises: a first heat radiation part including an upper portion on which the light source module is disposed, a lower portion connected to the upper portion, and a receiver (31 OR); and a second heat radiation part including an inner portion which is disposed in the receiver of the first heat radiation part, and an outer portion which encloses the lower portion of the first heat radiation part, wherein the second heat radiation part has the optical transmittance, and wherein the outer portion of the second heat radiation part emits outwardly a part of light incident from the inner surface of the cover (100, 100'). a heat sink having an optical transmittance; a light source module including a substrate disposed on the heat sink and a light emitting device disposed on the substrate; and a cover (100, 100') which is disposed on the light source module and outwardly emits a part of light from the light source module, wherein the cover (100, 100') has an inner surface which reflects a part of light from the light emitting device, and wherein the heat sink receives the light from the inner surface of the cover (100, 100') and outwardly emits a part of the received light, Characterized in that the heat sink comprises: a first heat radiation part including an upper portion on which the light source module is disposed, a lower portion connected to the upper portion, and a receiver (31 OR); and a second heat radiation part including an inner portion which is disposed in the receiver of the first heat radiation part, and an outer portion which encloses the lower portion of the first heat radiation part, wherein the second heat radiation part has the optical transmittance, and wherein the outer portion of the second heat radiation part emits outwardly a part of light incident from the inner surface of the cover (100, 100'). wherein the cover (100, 100') has an inner surface which reflects a part of light from the light emitting device, and wherein the heat sink receives the light from the inner surface of the cover (100, 100') and outwardly emits a part of the received light, Characterized in that the heat sink comprises: a first heat radiation part including an upper portion on which the light source module is disposed, a lower portion connected to the upper portion, and a receiver (31 OR); and a second heat radiation part including an inner portion which is disposed in the receiver of the first heat radiation part, and an outer portion which encloses the lower portion of the first heat radiation part, wherein the second heat radiation part has the optical transmittance, and wherein the outer portion of the second heat radiation part emits outwardly a part of light incident from the inner surface of the cover (100, 100'). a first heat radiation part including an upper portion on which the light source module is disposed, a lower portion connected to the upper portion, and a receiver (31 OR); and a second heat radiation part including an inner portion which is disposed in the receiver of the first heat radiation part, and an outer portion which encloses the lower portion of the first heat radiation part, wherein the second heat radiation part has the optical transmittance, and wherein the outer portion of the second heat radiation part emits outwardly a part of light incident from the inner surface of the cover (100, 100'). wherein the second heat radiation part has the optical transmittance, and wherein the outer portion of the second heat radiation part emits outwardly a part of light incident from the inner surface of the cover (100, 100').