A thienopyrazine compound which is useful for an organic semiconductor material. An organic field effect transistor, which includes an organic semiconductor layer that is easily produced from an organic semiconductor material containing the thienopyrazine compound by a coating method or a printing method, and which exhibits high carrier mobility and high on/off current ratio; and an organic field effect transistor which has ambipolar characteristics. The thienopyrazine compound is represented by chemical formula (I): wherein Ar1 and Ar2 each represents an aryl group, and R1 and R2 each independently represents a hydrogen atom, an alkyl group or an aryl group; or alternatively R1 and R2 represent a group having a ring formed by combining R1 and R2 together.