A thin-film transistor array panel includes an insulation substrate, a gate line disposed on the insulation substrate, a gate insulating layer disposed on the gate line, a semiconductor layer disposed on the gate insulating layer, a data line disposed on the semiconductor layer and including a source electrode, a drain electrode disposed on the semiconductor layer and facing the source electrode, a first electrode disposed on the gate insulating layer, a first passivation layer disposed on the first electrode and including silicon nitride, a second passivation layer disposed on the first passivation and including silicon nitride, and a second electrode disposed on the passivation layer, in which a first ratio of nitrogen-hydrogen bonds to silicon-hydrogen bonds in the first passivation layer is different from a second ratio of nitrogen-hydrogen bonds to silicon-hydrogen bonds in the second passivation layer.