PURPOSE: To provide a lagge lighting output and reduce interference to a radio by shaping the output of an inverter lighting circuit by the use of a bridge, and supplying the resulting direct current to a lamp.

CONSTITUTION: The electrode heating terminal of an inverter lighting circuit 1 is connected to the electrode of a lamp 4, and the electrode is heated to reduce the starting voltage of the lamp 4. The voltage of the lamp starting voltage or higher is obtained from the inverter circuit 1. Then, a direct current voltage is obtained by the use of a bridge 2. This is changed to a direct current by the use of a smoothing coil 7 and a smoothing capacitor 6, and the resulting current is supplied to the lamp 4. Since a direct current having less AC component can be provided, the flicker of the lamp 4 is eliminated, and by the amount that the flicker is eliminated, larger output can be provided.