To use an LED to reveal the emitting light of a red color, a yellow color and a bluish green color, and emit the light of respective colors in a well-balanced condition by supplying a direct current to a light emitting diode by rectifying AC voltage supplied from the same AC power source with respective electric circuits, and equalzing impedances of the electric curcuits of respective lamps.

Electric circuits 11a of a yellow light emitting unit 9b and electric circuits 11b of a green light emitting unit 9a are respectively and separately connected to an insulating transformer 13 through rectifiers 12, and emit the light when electric power is supplied from an AC power source, but the respective electric circuits 11a of the yellow light emitting unit 9b and the respective electric circuits 11b of the green light emitting unit 9a are connected in series to each other, and the insulating transformer 13 connected to the yellow light emitting unit 9b supplies electric power to the respective rectifiers 12 and 12 by transforming AC 100V to 200V. Therefore, DC 100V is respectively supplied to the electric circuits 11a and 11b of the two light emitting units 9a and 9b whose impedances are equal to each other, and luminous intensity of the yellow light emitting unit and the green light emitting unit can be secured.