PURPOSE: To easily control the tunnel current of a semiconductor device by opening a window through the first substance layer and making exciting light to incident on the second substance layer through the window so as to produce electron and a hole in the second substance layer.

CONSTITUTION: An n-InGaAs layer A5, InAlAs layer A4, InGaAs layer A3, GaAsSb layer A2, and n-InGaAs layer A1 are successively grown on a semi- insulating InP substrate SUB and mesa-etching is performed up to the surface of the layer A5 from the surface of the layer A1 so as to form a recessed section which becomes part of a window W into the layer A1. Then an SiO2 film P1 is formed by a chemical vapor-depositing method. An electrode contact window, etc., is formed by selectively etching the SiO2 film P1 by a photolithographic method and electrodes C1 and C2 formed. The window W for making light to incident on the layer A2 is formed of the opening of the electrode C1 and the recessed section of the first substance layer A1. When the layer A2 is irradiated with a Kr laser beam as exciting light, a hole is produced in the layer A2 and electron is moved to the layer A3. As a result, the resonance level E1 varies to produce a resonant state and the tunnel current of this semiconductor device changes.