PURPOSE: To provide a subminiature monolithic variable electric device and a device provided with it.

CONSTITUTION: This device is provided with a substrate 43 for forming one electrode of a capacitor 40a, a conductive member 145 formed monolithically with the substrate 43 for forming the other electrode of the capacitor 40a, mounting means 42 and 44 for mounting the member 145, deflecting a part of it so as to be brought closer/away to/from the substrate 43, storing energy when the member 145 is to be deflected from the normal position and trying to recover to the normal position by the stored energy and a control electrode 46a formed monolithically with the substrate 43 for generating an electric field for deflecting a part of the member 145 from the normal position by the impression of control signals and changing the capacitance of the capacitor 40a.