An organic TFT including a gate electrode, a source electrode and a drain electrode insulated from the gate electrode, and an organic semiconductor layer that is insulated from the gate electrode and contacts the source electrode and the drain electrode. The length of portions of edges of the source electrode, which contact the organic semiconductor layer and face the drain electrode, is greater than the length of portions of edges of the drain electrode, which contact the organic semiconductor layer and face the source electrode to reduce the contact resistance between the source electrode and the organic semiconductor layer.