A discharge lamp lighting circuit includes a DC/AC converter, a starting circuit, a control unit, a plurality of switching elements driven by the control unit and a series LC resonance circuit. At the time of lighting the discharge lamp, the driving frequency of the switching elements is set to a value higher than a resonance frequency at a time of lighting the discharge lamp thereby to drive and control the switching elements. When the driving frequency reduces and the extinction of the discharge lamp is detected, the driving frequency is shifted to a frequency region which is higher than a resonance frequency at a time of extinguishing the discharge lamp thereby to restart the lamp. Further, when the driving frequency reduces to a value lower than the resonance frequency at a time of lighting the discharge lamp during the lighting of the discharge lamp, the driving frequency is restored to a frequency region higher than the resonance frequency at a time of lighting the discharge lamp.