The present invention relates to a flat panel display including a gate insulating layer having opening defining pixels. The flat panel display apparatus includes: a substrate; a source electrode and a drain electrode formed on the substrate; a semiconductor layer contacting the source electrode and the drain electrode; an insulating layer formed above the source and drain electrodes and a pixel electrode, and including an opening; a gate formed above the insulating layer; and the pixel electrode partially exposed by the opening of the insulating layer, wherein the pixel electrode is directly formed on the substrate, and is directly connected to one of the source and the drain electrodes or is extended from one of the source and the drain electrodes. The insulating layer acts as a gate insulating layer and a pixel definition layer defining the pixel electrode.