PURPOSE: To contrive to reduce the cost of the TFT (thin film transistor) by the elimination of packaging by a method wherein the TFT is formed on the surface of an insulation substrate, a surface protection film being formed thereon, and an electrode extending to the end of the substrate being then formed.

CONSTITUTION: The TFT composed of an Si film 12, a diffused layer 13, a gate oxide film 14, and a gate electrode 15 is formed on the surface of the sapphire substrate 11. A lead-out electrode 17 is formed by extending to the end of the substrate 11. The surface of the TFT is protected with the surface protection film 18 of epoxy resin or Si oxide film, etc., and a contact terminal consisting of a Cr film 19, an Au-plated film 20, etc. is formed on the electrode 17 at the end of the substrate 11.