To dispense with a laser processing by a method wherein a structure consisting of a movable electrode and one pair of fixed electrodes on both its sides is formed on an etching stop film on a silicon wafer and after the movable electrode is made to oppose to a recess formed in the glass substrate and bonded to the substrate, a film on the surface of the wafer is removed and the movable electrode is provided in a form that it is held between the one pair of the fixed electrodes.

Oxide films 21 are respectively formed on both surfaces of a silicon wafer 20 and thereafter, the film 21 on the surface on one side of both surfaces is removed and an Ni film 22 is formed on the surface on one side. After the film 22 is patterned, the wafer 20 is subjected to anisotropic etching using the film 21 as an etching stop layer, a movable electrode 26 consisting of a single crystal layer is formed on the film 21 and gaps are slightly opened on both sides of the electrode 26 to form one pair of fixed electrodes 27 and 28. After the film 22 is removed, a structure 20a consisting of the electrodes 26, 27 and 28 is anode-junctioned with a glass-substrate 10 in such a way that the electrode 26 opposes to a recess 11 formed in the substrate 10 and after that, the film 21 is removed. Thereby, a semiconductor inertial sensor 30 floated over the recess can be obtained holding the electrode 26 between the one pair of the fixed electrodes.