A lamp lighting apparatus includes an arc spot movement detector (5) for monitoring an DC voltage Vb which is the bus voltage of an inverter (3), and for detecting a movement of an arc spot which appears before a lamp 1 enters a state where human beings can recognize a flicker of the lamp (1), and, when the arc spot movement detector (5) detects a movement of the arc spot, controls a switch (2a) of a DCDC converter (2) so as to suppress the movement of the arc spot.