PURPOSE: To simplify the manufacturing processes for cutting down the cost by a method wherein electrodes are selectively deposited on the side and bottom surfaces of a deep silicon trench formed by anisotropical etching step.

CONSTITUTION: A mask layer 11 is formed on the whole surface of a silicon wafer 10 having a crystalline directional surface as a main surface and then an opening part 12 to form a cantilever is provided on the layer 11. Next, an electrode layer for leadingout wiring of upper and lower electrodes is formed on the surface having the opening part 12 and then silicon is anisotropically etched away to form the wiring 14 for upper electrode 13 and lower electrode 14. At this time, a part of the wiring 14 is brought into contact with the silicon in the opening part 12. Next, the cantilever is formed by crystal axial anisotropical etching step. Next, a metal is deposited on the exposed silicon and electrode layer by selective deposition step. Through these procedures, the manufacturing processes are simplified to cut down the cost.