A flat panel display apparatus includes a gate insulating layer having openings which define 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; a gate formed on the substrate; an insulating layer formed between the source and drain electrodes and the gate, and including an opening; and a pixel electrode partially exposed by the opening of the insulating layer. The insulating layer acts as a gate insulating layer and a pixel definition layer defining the pixel electrode.