A semiconductor device includes a first electrode formed on a substrate, the first electrode being a first electrical potential; and a second electrode formed on the first electrode, the second electrode including a signal wiring that transmits a signal and a planar electrode part with a prescribed area. A shape of the first electrode corresponding to the planar electrode part is made into a slit shape such that a longitudinal direction of a slit is parallel to a direction in which the signal proceeds in the planar electrode part.