Aspects of the invention can provide a thin-film transistor having good transistor characteristics and operable with a low driving voltage, a method of producing such a thin-film transistor, a high-reliability electronic circuit, a display, and an electronic device. In an exemplary thin-film transistor according to the invention, a gate electrode can be formed on a substrate via an underlying layer, and a gate insulating layer can be formed on the substrate such that the gate electrode is covered with the gate insulating layer. A source electrode and a drain electrode are formed on the gate insulating layer such that they are separated from each other by a gap formed just above the gate electrode. An organic semiconductor layer can be formed thereon such that the electrodes are covered with the organic semiconductor layer. A region between the electrodes of the organic semiconductor layer functions as a channel region. A protective layer can be arranged on the organic semiconductor layer. This thin-film transistor is characterized in that the organic semiconductor layer is formed after the gate insulating layer is formed, and the gate insulating layer has the capability of causing the organic semiconductor layer to be aligned.