A backlight unit, with a parallel configuration of plural lamps, having improved reliability is disclosed. The backlight unit driver includes: first and second lamps connected parallel to each other; a DC/AC inversion portion inverting a DC voltage into an AC voltage to apply the AC voltage to the lamps; a transformer transforming the AC voltage from the DC/AC inversion portion; a positive polarity AC signal compensator compensating an electric current difference between the first and second lamps using positive polarity AC signals from the first and second lamps; and a negative polarity AC signal compensator compensating the electric current difference between the first and second lamps using negative polarity AC signals from the first and second lamps.