A flat display apparatus has a flat display panel; a frame that is installed on a rear face side of the display panel; a cover that covers at least a rear face side of the frame; and a high-voltage power supply that applies high voltage to the display panel. The high-voltage power supply has a plurality of cases, each of which encloses one or more transformers and rectifier circuits, and obtains high voltage by connecting the plurality of cases in series, and the plurality of cases are arranged in a space created between the frame and the cover so as to be disposed on a plane in parallel with a screen of the display panel.