Abstract: A thin film transistor array panel is provided, which includes a substrate; a gate line formed on the substrate and including a gate electrode; a gate insulating layer formed on the gate line; a semiconductor layer formed on the gate insulating layer; a plurality of ohmic contacts formed on the semiconductor layer; source and drain electrodes formed on the ohmic contacts; a passivation layer formed on the source and the drain electrodes and having a first contact hole exposing a portion of the drain electrode and an opening exposing a first portion of the semiconductor layer and having edges that coincide with edges of the source and the drain electrodes; and a pixel electrode formed on the passivation layer and contacting the drain electrode through the first contact hole.