A rear turn lamp having a divided structure comprising a first lamp unit provided to a fixed portion of a vehicle body and a second lamp unit provided to a movable portion of the vehicle body, wherein the first lamp unit comprises: a controller; one or a plurality of first light sources (210_1... 210_M); a first lighting circuit configured to turn on the one or plurality of first light sources, and wherein the second lamp unit comprises: a plurality of second light sources (310_1...310_N); and a second lighting circuit configured to turn on the plurality of second light sources in a predetermined order in response to a first start signal received from the controller; characterized in that the controller is provided only in the first lamp unit and configured as a microcontroller and configured to receive a turn synchronization signal (TURN_SYNC) which is a pulse signal repeatedly switched between a high and low level with a predetermined period, wherein the controller is adapted to be coupled to a vehicle-side Electronic Control Unit, the controller and the first lighting circuit are mounted on the same substrate and are coupled via printed wiring, the first lamp unit and the second lamp unit are coupled via a first line, the controller is configured to transmit the first start signal (LID_START) in response to an assertion of the turn synchronization signal (TURN _SYNC) to the second lighting circuit, the second lighting circuit is configured to turn on the plurality of second light sources in a predetermined order in response to the reception of the first start signal (LID_START), the first lighting circuit is configured to turn on the one or the plurality of first light sources after the second lighting circuit has turned on the plurality of the second light sources (310_1...310_N). wherein the first lamp unit comprises: a controller; one or a plurality of first light sources (210_1... 210_M); a first lighting circuit configured to turn on the one or plurality of first light sources, a controller; one or a plurality of first light sources (210_1... 210_M); a first lighting circuit configured to turn on the one or plurality of first light sources, and wherein the second lamp unit comprises: a plurality of second light sources (310_1...310_N); and a second lighting circuit configured to turn on the plurality of second light sources in a predetermined order in response to a first start signal received from the controller; characterized in that the controller is provided only in the first lamp unit and configured as a microcontroller and configured to receive a turn synchronization signal (TURN_SYNC) which is a pulse signal repeatedly switched between a high and low level with a predetermined period, wherein the controller is adapted to be coupled to a vehicle-side Electronic Control Unit, the controller and the first lighting circuit are mounted on the same substrate and are coupled via printed wiring, the first lamp unit and the second lamp unit are coupled via a first line, the controller is configured to transmit the first start signal (LID_START) in response to an assertion of the turn synchronization signal (TURN _SYNC) to the second lighting circuit, the second lighting circuit is configured to turn on the plurality of second light sources in a predetermined order in response to the reception of the first start signal (LID_START), the first lighting circuit is configured to turn on the one or the plurality of first light sources after the second lighting circuit has turned on the plurality of the second light sources (310_1...310_N). a plurality of second light sources (310_1...310_N); and a second lighting circuit configured to turn on the plurality of second light sources in a predetermined order in response to a first start signal received from the controller; characterized in that the controller is provided only in the first lamp unit and configured as a microcontroller and configured to receive a turn synchronization signal (TURN_SYNC) which is a pulse signal repeatedly switched between a high and low level with a predetermined period, wherein the controller is adapted to be coupled to a vehicle-side Electronic Control Unit, the controller and the first lighting circuit are mounted on the same substrate and are coupled via printed wiring, the first lamp unit and the second lamp unit are coupled via a first line, the controller is configured to transmit the first start signal (LID_START) in response to an assertion of the turn synchronization signal (TURN _SYNC) to the second lighting circuit, the second lighting circuit is configured to turn on the plurality of second light sources in a predetermined order in response to the reception of the first start signal (LID_START), the first lighting circuit is configured to turn on the one or the plurality of first light sources after the second lighting circuit has turned on the plurality of the second light sources (310_1...310_N).