In a discharge lamp lighting apparatus for lighting a discharge lamp comprises a starter which generates high voltage at initiation so as to generate dielectric breakdown in the discharge container of the discharge lamp; and a power supply circuit which supply discharge current to the discharge lamp, wherein the power supply circuit has an output current modulation circuit which modulates a magnitude of current flowing through the discharge lamp at least in a steady state, wherein the output current modulation circuit controls a change speed in case a lamp current per square millimeter in a cross section of the cathode electrode is increased, to be 3.9 A per millisecond or less, wherein the power supply circuit carries out control in which an average current in the steady state is set so that an odd-shape portion is formed at a tip of the cathode electrode.