PURPOSE: To narrow an interval between a conductor, to increase capacity and to reduce an occupied area by thinning the thickness of an Si substrate where corresponding to the slat-shaped conductor.

CONSTITUTION: The thickness Ta of the Si substrate 1 is made thin thickness Tb where corresponding to the slat conductor 4, and a grounding conductor 2a is mounted. Accordingly, capacity is increased, the augmentation of the occupied area is prevented and the degree of integration can be improved by simple structure, in which the substrate is thinned only at a slat capacity forming section, in the semiconductor device containing capacity.