Abstract: A light control device for a high frequency lighted fluorescent lamp includes a high frequency variable voltage power source. A first impedance element (a capacitor and inductor in series) is provided between the terminals of the lamp on the side opposite to the power source. A second impedance element (an inductor) is connected between the power source and the terminals of the lamp, and a third impedance element (a capacitor) is connected across the lamp on the power source side. A constant power source circuit supplies, upon starting of the lamp, constant power to the first impedance element to thereby apply substantially constant cathode pre-heating current and starting voltage and applies, during the lighting of the lamp, substantially constant cathode heating current. The control circuit is capable of pre-set light control. The light control device suppresses beat interference and fluorescent lamp noises due to the electric field radiated from the lamp. Rapid and instant starting is enabled.