PURPOSE: To obtain the titled IC having high density by a method wherein an epitaxial layer is pinched by using an isolating diffusing layer from the upper section of a wafer and changed into a high resistor, and a collector and a load resistance can be unified to a transistor using the epitaxial layer as the collector.

CONSTITUTION: B Is is diffused to a p type substrate, a reserve isolating layer 22 is formed and the epitaxial layer 23 is stacked. B Is diffused from the upper section of the n- layer 23, and the isolating layers 24A are shaped, and connected to the layer 22. A p layer 24B is formed at the same time, and an n+ layer 25 is diffused while surrounding the layer 24B, used as both ends of the resistor and connected to wiring metals 29. That is, high resistance is shaped by employing the epitaxial layer as the resistor and positioning the p layer 24B in the epitaxial layer 23. The depth of the p layer 24B is made approximately half the epitaxial layer 23 and the high resistance value of approximately twice as high as when using epitaxial layer itself, the potential of the epitaxial layer is made considerably higher than the substrate, or remarkably high resistance value is acquired when the epitaxial layer is brought to low concentration and depletion layer diffuses to the epitaxial layer. According to this constitution, the resistor can be formed with high density without increasing processes.