The invention provides a thin film transistor (TFT) array panel that includes an insulating substrate; a gate line formed on the insulating substrate and having a first layer of an Al containing metal, a second layer of a Cu containing metal that is thicker than the first layer, and a gate electrode; a gate insulating layer arranged on the gate line; a semiconductor arranged on the gate insulating layer; a data line having a source electrode and arranged on the gate insulating layer and the semiconductor; a drain electrode arranged on the gate insulating layer and the semiconductor and facing the source electrode; a passivation layer having a contact hole and arranged on the data line and the drain electrode; and a pixel electrode arranged on the passivation layer and coupled with the drain electrode through the contact hole.