A first LED substrate and a second LED substrate are included each of which includes: on a main surface thereof, a plurality of LEDs connected in series in a longitudinal direction; a first connector including (i) a first terminal disposed on one of short sides of the LED substrate and connected to an anode of an LED positioned first among the LEDs connected in series, and (ii) a second terminal connected to a cathode of another LED positioned last among the LEDs connected in series. The second terminal of the first LED substrate and the first terminal of the second LED substrate are interconnected. The first terminal of the first LED substrate is connected to a positive terminal of a power circuit and the second terminal of the second LED substrate is connected to a negative terminal of the power circuit.