The present invention aims to provide an organic thin film transistor that is superior in stability in the atmosphere and that has a high operation speed. The organic thin film transistor according to the present invention includes three kinds of terminals consisting of a gate electrode, a source electrode, and a drain electrode, an insulator layer that insulates the gate electrode from the source electrode and from the drain electrode, and an organic semiconductor layer; the terminals, the insulator layer, and the organic semiconductor layer being disposed on a substrate; the organic thin film transistor controlling a source-to-drain electric current by a voltage applied to the gate electrode, and the organic thin film transistor is characterized by further including a crystallinity control layer that is formed from a crystalline compound that controls crystallinity of the organic semiconductor layer, and is characterized in that the organic semiconductor layer is formed on the crystallinity control layer and contains a compound having heterocyclic groups or a compound having a quinone structure. The organic thin film light-emitting transistor according to the present invention is characterized in that either one of the source electrode and the drain electrode of the organic thin film transistor is formed of a hole-injecting electrode, and the other electrode is formed of an electron-injecting electrode.