PURPOSE: To provide a structure which can form contact between a gate electrode inside a groove and a metallic electrode by an easy method.

CONSTITUTION: This is an insulated electrode which has a groove approximately uniform in width at specified places on the surface of a substrate and an insulator (insulating film 37) on the surface of the substrate, and in which the insulating electrode (insulated gate 7) buried in the said groove is made, being overlapped partially with this insulator, and in the overlapped region, a contact window 20 is opened in the insulating film (interlayer insulating film 6) of the insulating electrode, and in the section of the contact window, the conductor (gate electrode 5) of the insulated electrode is connected to another electrode (gate metal 17) for connection.