Patent ID: 7741850

Claim:
An electric potential measuring apparatus operable to measure an electric potential of a measurement object, comprising: a substrate formed of a semiconductor material; an insulator layer; a plurality of detecting electrodes provided on the substrate with the insulator layer therebetween using MEMS techniques; a capacitance modulating unit configured to modulate a coupling capacitance between the detecting electrodes and the measurement object; a detecting unit configured to detect an electric potential of the measurement object based on a signal detected by the detecting electrodes; and an insulator portion formed in at least a portion of the substrate, wherein the insulator portion is provided at least one of a position where a length of an electric path between the detecting electrodes that is created in the substrate through a stray capacitance caused in the insulator layer is elongated, a position where the electric path is narrowed in a thickness direction of the substrate, and a position where the electric path is insulated.