PURPOSE: To improve the accuracy of oscillation frequencies by a method wherein externally provided vibrators are contained the integrated circuit.

CONSTITUTION: A substrate surface insulating film 2, wiring layers 3 consisting of an n+ type diffusion layer, metal terminals 4, a piezoelectric vibrating substance 5 formed by performing a sputtering method etc., on CdS, etc., and a protective film 6 consisting of phospho-silicate glass, etc., which are covering the vibrating substance are formed on an Si semiconductor substrate 1. The other part on the substrate includes an amplifying circuit for oscillation, and, between the terminals 3 connecting to the vibrating substance, the one is used as the output terminal for the amplifying circuit and the other as the input terminal. An oscillation amplifying circuit 7 in the equivalent circuit is driven by a power source circuit 8.