To provide a capacitance-type pressure sensor wherein linearity in input/output characteristics is good, the sensor is compact but highly sensitive, and a measurement range is wide.

A periphery of a diaphragm 2 is supported by a base 1, and the diaphragm 2 approximately entirely flexes like a dome with a pressure applied. A center of a movable electrode plate 10 for maintaining a flat shape is locally coupled and supported by the center of the diaphragm via a neck 11, wherein when the diaphragm 2 flexes, the movable electrode plate 10 shifts in parallel in its thickness direction, but the flat shape can be held. Thus a fixed electrode 7 placed on a glass substrate 5 faces the movable electrode plate 10 in parallel with an appropriate distance, so that even if the distance between the fixed electrode 7 and the movable electrode plate 10 varies according to the flex of the diaphragm 2, distances at respective parts are approximately equal, thereby obtaining good linearity over a wide range.