A method of manufacturing a thin film transistor array panel is provided, the method includes: a substrate; a data line disposed on the substrate; an interlayer insulating layer disposed on the data line; a gate line disposed on the interlayer insulating layer and including a gate electrode; a gate insulating layer disposed on the gate line and the interlayer insulating layer, the gate insulating layer and the interlayer insulating film having a contact hole exposing the data line; a first electrode disposed on the gate insulating layer and connected to the data line through the contact hole; a second electrode disposed opposite the first electrode with respect to the gate electrode; an organic semiconductor disposed on the first and the second electrodes and contacting the first and the second electrodes; and a passivation member disposed on the organic semiconductor.