The MS7212A is an absolute silicon micro-machined pressure sensor for harsh environment. A vacuum reference cavity is sealed on top of the sensitive silicon membrane by the anodic bonding of a Pyrex cap. The pressure, applied on the backside, is converted in electrical signal by piezo-resistors implanted in the silicon membrane. To improve the sensor stability, a drilled Pyrex is bonded on the backside. As the pressure port consists of Pyrex and silicon, both stable in most of the chemicals, the MS7212 is suitable for media-resistive applications.