An object of the present invention is to reduce power consumption and heat generation in an A/S separating circuit for preventing an inflow of an auxiliary voltage into a sustain discharge voltage source in a Y electrode driver circuit or an X electrode driver circuit of a plasma display apparatus. In the present invention, a sustain-voltage generating circuit in the Y-electrode driver circuit or the X-electrode driver circuit is configured of a bidirectional switch, and the A/S separating circuit is removed.