To provide a discharge lamp lighting device capable of suppressing striation in which a discharge lamp emits striped light, without making the entire device expensive and large by adding no special component or minimizing additional components.

An output from a feedback means 13 is applied as a driving voltage to at least a pair of voltage driven switching circuits 8, 9 for switching a direct current voltage by alternately switching it on and off. A constant voltage element 18, 19, which has a different voltage value for each, to fix a driving voltage applied to each switching device is provided in each switching device. Due to a difference in the driving voltage applied, duration in which each switching device is switched on differs, and as a result, striation is suppressed since a wave form of a lamp current of a discharge lamp 16 differs depending on if it is positive or negative.