A thin film transistor array substrate includes a thin film transistor including a gate electrode, an active layer, and source and drain electrodes, a pixel electrode on a same layer as the gate electrode, a lower electrode of a capacitor, the lower electrode being on the same layer as the gate electrode, a first insulating layer on the gate electrode and the lower electrode, a second insulating layer between the active layer and the source and drain electrodes, an upper electrode on the first insulating layer, the upper electrode including a first layer made of a same material as the active layer, and a second layer made of a same material as the source and drain electrodes, and a third insulating layer that covers the source and drain electrodes and the upper electrode and exposes the pixel electrode.