Sealed diaphragm pressure sensor

A pressure sensor includes a pressure detecting chamber sectionally formed by a diaphragm for receiving measured pressure and a semiconductor chip having a diaphragm as a pressure-sensitive portion is equipped in the pressure detecting chamber. Electrically insulating pressure transmitting liquid for transmitting the measured pressure received by the diaphragm to the semiconductor chip is sealingly filled in the pressure detecting chamber. Also, an electrical circuit for signal processing is equipped around the pressure-sensitive portion at the surface site of the semiconductor chip. The electrical circuit is coated by protection film. Electrical conducting film set to ground potential is formed as the uppermost layer of the semiconductor chip on the surface of the protection film.