a semiconductor pressure sensor having a cylindrical housing with an opening formed at its tip end which is exposed to a pressure atmosphere and a metal diaphragm for receiving pressure which is formed in a wall of the cylindrical housing defining the opening . a metal oxide layer is formed in a surface of the metal diaphragm by oxidizing the surface of the metal diaphragm , and a glass layer is formed on the metal oxide layer . a semiconductor chip , on which a strain gauge is formed , is firmly and surely bonded to the metal diaphragm through the glass layer by virtue of the metal oxide layer . this semiconductor pressure sensor can measure high pressure with sufficient sensitivity and high accuracy .