PURPOSE: To make it possible to obtain a three-dimentional sensor easily and inexpensively, by preparing on an insulating substrate a silicon thin film in which an amorphous phase and a microcrystalline phase exist mixedly, and by providing a pair of electrodes on the opposite sides of the thin film.

CONSTITUTION: An amorphous silicon thin film conductor 2 can be made to have a dark current conductivity of a large value of 0.1S.cm-1 or above by a method wherein an amorphous phase and a microcrystalline phase made up of silicon mixed crystal are made to exist mixedly, and thereby a small-sized resistor can be formed on an insulating substrate 1. The temperature coefficient of the dark current conductivity is 1%/K or below, and the thermoelectric power is 10μV/K at least. Thereby, a resistor not requiring temperature compensation, a high-frequency power sensor, an infrared sensor, a strain sensor, a pressure sensor, a load cell, etc. can be constructed by employing the titled material.