To provide a power supply device for a lighting apparatus, enabling stable lighting control operation without light flicker of an LED lighting apparatus and a fluorescent lamp inverter lighting apparatus, having large power consumption, by means of a phase control dimmer.

A power control element Q1 is disposed between a diode bridge DB, disposed in an AC input unit of a power supply, for performing full-wave rectification of commercial AC power supply for the power supply incorporated in an LED lighting apparatus 4 and a capacitor C4 for rectification. Simultaneously with a triac T in a phase control dimmer 1 turning ON, the power control element Q1 starts conduction operation, and further, the power control element Q1 is driven not to make an oscillation current flow into the input current of the power supply. By this, the triac T in the dimmer secures phase control operation, so as to solve the problem.