Acoustic sensor and microphone

An acoustic sensor comprising:

• a semiconductor substrate comprising a back chamber;
• a conductive diaphragm arranged on an upper side of the semiconductor substrate;
• an insulating fixed film fixed on an upper surface of the semiconductor substrate to cover the conductive diaphragm with a gap;
• a conductive fixed electrode film arranged on the insulating fixed film at a position facing the conductive diaphragm;
• an extraction wiring extracted from the conductive fixed electrode film;
• and
• an electrode pad, to which the extraction wiring is connected,
• wherein the acoustic sensor converts an acoustic vibration to change electrostatic capacitance between the conductive diaphragm and the conductive fixed electrode film,
• wherein a plurality of acoustic perforations are opened in a back plate comprising the insulating fixed film and the conductive fixed electrode film, and
• wherein at least the extraction wiring, and a region in the vicinity thereof, does not comprise the acoustic perforation or comprise an acoustic perforation of small opening rate compared to an acoustic perforation arranged in other regions, except in a case in which an acoustic perforation is not arranged in the extraction wiring, and an opening rate of an acoustic perforation arranged in the region in the vicinity of the extraction wiring and an opening rate of an acoustic perforation arranged in other regions, excluding the extraction wiring and the region in the vicinity of the extraction wiring, are equal.