PURPOSE: To enable application as an N-P-N transistor, a P-N-P transistor or a thyristor by diffusing and forming a P layer and a ring-shaped P layer surrounding the P layer to the upper surface of an N substrate, diffusing and forming an N layer at the center of the upper surface of the ring-shaped P layer and connecting terminals to each of the N substrate, the P layer, the N layer and the P layer.

CONSTITUTION: The device can be formed easily through conventional manufacturing technique because of the same constitution as the N-P-N transistor when the P layer 17 and the terminal 24 of the layer 17 are removed. When the terminals 23, 22 and 21 are used and these terminals are used as the terminals of an emitter, a base and a collector in succession, the device functions as the N-P-N transistor. When the terminals 22, 21 and 24 are used and these terminals are employed as the terminals of an emitter, a base a collector in succession, the device functions as the P-N-P transistor. When the terminals 23, 22 and 24 are used and these terminals are employed as the terminals of a cathode, a gate and an anode in succession, the device functions as the thyristor.