To accurately detect a voltage or a current of a discharge lamp to perform abnormality detection or output adjustment while maintaining a light output instructed by a PWM signal, in a burst dimming type discharge lamp lighting device.

The discharge lamp lighting device comprises an inverter circuit 1 which converts a DC voltage to a high frequency and supplies it to a discharge lamp LF; a detection timing circuit 4 which inputs PWM signal 3 for performing dimming in a ratio of an ON-period to an OFF-period, and switches, according to the PWM signal 3, an output of the inverter circuit 1 from an intermittent lighting state for flashing the discharge lamp FL to a continuous lighting state at an optional time so that a light output equal to an average light output in the intermittent lighting state can be obtained in the continuous lighting state; and a detection circuit 5 which detects at least one of a voltage and a current of the discharge lamp FL in a state of being switched to the continuous lighting state by the detection timing circuit 4.