The lamp lighting circuit prevents a malfunction in which a lamp is tuned on momentarily during an initial stage of the power input. When the power source is lit, the malfunction prevention circuit prevents the activation of the oscillation circuit and/or the driving circuit 3a until when the output control circuit 5 starts normal operation and outputs the output control signal that controls the lighting/non-lighting of the lamp. When a lamp lighting command is input to the output control circuit, the output of the oscillation circuit is transmitted to the power control element via a driving circuit, and the power control element is driven. Consequently a voltage is generated on the secondary side coil of a boosting transformer so that the lamp 1 is lit.