A thin film transistor array panel includes: a gate line disposed on a substrate and including a gate electrode, a semiconductor layer including an oxide semiconductor disposed on the substrate, and a data wire layer disposed on the substrate and including a data line intersecting the gate line, a source electrode connected to the data line, and a drain electrode facing the source electrode. In addition, at least one of the data line, the source electrode or the drain electrode of the data wire layer includes a barrier layer and a main wiring layer disposed on the barrier layer. The main wiring layer includes copper or a copper alloy. Also, the barrier layer includes a metal oxide, and the metal oxide includes zinc.