A discharge lamp lighting device includes a high frequency power supply for supplying high frequency power to the discharge lamp via a first impedance element, a DC power supply for applying DC voltage to the discharge lamp via a second impedance element, a dimming control circuit for carrying out a dimming of the discharge lamp by controlling the power supplied to the discharge lamp, a DC voltage detection circuit for detecting a DC component of the voltage applied to the discharge lamp, and an output correction unit for making a correction to the power supplied to the discharge lamp in accordance with a value detected by the DC voltage detection circuit. It can light the discharge lamp stably regardless of a variation in temperature.