PURPOSE: To obtain a high tension vibrating element not producible by a design using boron only by a method wherein a first epitaxial layer is allowed to grow, composed of an etching-resistant high concentration p-type silicon simultaneously doped with carbon as well as boron, for the preparation of substrate regions for vibrating beams.

CONSTITUTION: On an n-type silicon substrate 1 cut along the plane 100, a film 201 is formed of a silicon oxide or a silicon nitride, and the film 201 is removed from a specified region 202 by photolithography. Epitaxial growth is caused to proceed at locations on the substrate 1 specified for the formation of vibrating beams 3 and 4, which results in a first epitaxially grown p-type silicon layer 203, not less than 3×1019/cm3 in impurity concentration approximately, during the growth of which the silicon is doped not only with boron but also with carbon. Vibrating beams 3 and 4 produced by this method are high in initial tension, with their range of movement wider in the compression side. This design enables the production of high tension vibrating beams 3 and 4 which the technique using boron only has failed.