Patent ID: 7928519

Claim:
A capacitance sensor comprising: a silicon substrate having a hole or a recess whose dimension becomes smaller toward a rear side thereof and whose section is trapezoidal; a first metal layer that is provided on a surface of the silicon substrate and is opposed to the hole or the recess; a first insulation layer formed on the first metal layer; a second insulation layer opposed to the first insulation layer with predetermined spacing; a second metal layer provided with an upper surface and one or more side surfaces thereof, and formed on the second insulation layer, wherein the second metal layer includes a portion directly facing the first metal layer and a portion directly facing the hole or the recess, and faces an edge of the first metal layer above the hole or the recess, and a surface protection film configured to cover the upper surface and the side surfaces of the second metal layer, wherein the portion of the second metal layer directly facing the hole or recess is lower than the portion thereof directly facing the first metal layer, and the second metal layer has a step between the portion of the second metal layer directly facing the hole or recess and the portion thereof directly facing the first metal layer.