A capacitance type sensor has a semiconductor substrate having a vertically opened penetration hole, a movable electrode film arranged above the penetration hole such that a periphery portion opposes to a top surface of the semiconductor substrate with a gap provided, and a fixed electrode film arranged above the movable electrode film with a gap with respect to the movable electrode film. A concave portion having at least a part thereof formed by an inclined surface is provided in the top surface of the semiconductor substrate in a region of the top surface of the semiconductor substrate which overlaps the periphery portion of the movable electrode film.