An organic semiconductor diode comprises a hole transport layer which is arranged on an anode side and formed of an organic compound having a hole transport capability, and an electron transport layer which is arranged on a cathode side and formed of an organic compound having an electron transport capability. The hole transport layer and the electron transport layer are laminated one upon another. The cathode has a work function close to or smaller than the electron affinity of the electron transport layer, while the anode has a work function larger than that of the cathode. The organic semiconductor diode exhibits nonlinear current-voltage characteristics when a voltage is applied between the hole transport layer and the electron transport layer in contact with each other.