A thin film transistor array panel includes a substrate, gate lines, each including a gate pad, a gate insulating layer, data lines, each including a data pad connected to a source and drain electrode, a first passivation layer disposed on the data lines and the drain electrode, a first electric field generating electrode, a second passivation layer disposed on the first electric field generating electrode, and a second electric field generating electrode. The gate insulating layer and the first and second passivation layers include a first contact hole exposing a part of the gate pad, the first and second passivation layers include a second contact hole exposing a part of the data pad, and at least one of the first and second contact holes have a positive taper structure having a wider area at an upper side than at a lower side.