Abstract: To provide a composite electronic part capable of achieving small-sized formation as a whole by reducing a number of parts, a main plate structure and an electronic timepiece using the same. A composite electric part such as a main plate structure of an electronic timepiece, includes a nonconductive main body portion and at least one conductive portion supported by the nonconductive main body portion, the nonconductive main body portion includes a nonconductive carbon nanotube, the conductive portion includes a conductive carbon nanotube and is molded integrally with the nonconductive main body portion and at least two terminal portions exposed to surfaces of the nonconductive main body portion to give a transfer path of an electric signal between two contact portions of electric parts other than the composite electric part.