. . "The positional relationship of the one movable electrode 10 and the coplanar line 3 is shown in a plan view FIG. 12A, a side view FIG. 12B, and a perspective view FIG. 14A. Also, FIG. 13A is an equivalent circuit diagram of the movable electrode 10 and the coplanar line 3 shown in FIGS. 12B. In the drawings, C1 represents the capacitance between the movable electrode 10 and the ground line 3 g 1," . . .