Abstract: An electrostatic pressure sensor has a supporting diaphragm bonded to be held between first and second pedestal plates, a sensor chip supported on a top face of a center portion of the second pedestal plate. The supporting diaphragm has in the center portion thereof a large-diameter hole that forms a slit-shaped space between the first and second pedestal plates. The first pedestal plate has at least one inlet hole, for the fluid being measured, connecting to the slit-shaped space. The second pedestal plate has at least an outlet hole, connecting to the slit-shaped space, for directing the fluid being measured to the pressure-sensitive diaphragm of the sensor chip. The pedestal plate has an inlet hole of the first pedestal plate and an outlet hole of the second pedestal plate do not overlap each other in the direction of thickness of the first and second pedestal plates.

Abstract: An electrostatic pressure sensor includes a diaphragm, a sensor pedestal, a cover plate, a stationary electrode, and a movable electrode. The cover plate is bonded to an outer peripheral portion of the diaphragm on the opposite side from the sensor pedestal to form a pressure introduction chamber in cooperation with the diaphragm. The cover plate has a pressure introducing hole that introduces a medium to be measured into the pressure introduction chamber from a direction that is perpendicular to a surface of the diaphragm. The pressure introducing hole is arranged so as to be positioned in a range of between 50.0% and 70.0% from the center of the diaphragm along a direction of the surface of the diaphragm, when the radius of the diaphragm is defined as 100%.