In a discharge lamp lighting apparatus, increase modulation on lamp current with a pulse is carried out according to a modulation signal. At a start-up of the discharge lamp or immediately thereafter, the increase modulation is restrained, and in a lighting steady state of the discharge lamp, the restraining of the increase modulation is released, and wherein when the restraining of the increase modulation is released, in a transition period from immediately after the start-up of the discharge lamp to the lighting steady state, the restraining of increase modulation is gradually released.