Provided is a video signal line driver circuit capable of displaying a video with a high viewing quality even when gradation voltages of the same value are simultaneously selected as analog video signals.A voltage ladder 87 of a source driver 50 has formed therein gradation voltage supplement lines 91 extending to the outside of the source driver 50 from output terminals for outputting generated gradation voltages. The gradation voltage supplement lines 91 are grounded outside the source driver 50 via voltage supplement capacitors 90. Accordingly, even when gradation voltages of the same value are simultaneously selected as analog video signals, the voltage supplement capacitors 90 provide necessary current supplement to the voltage ladder 87, thereby inhibiting potential drop across the output terminals for outputting gradation voltages.