This paper presents a pressure sensor based on a variable capacitor formed by a movable polysilicon sealed membrane sensitive to pressure. When operated as a pressure sensor two operation regions are observed, an exponentially sensitivity region at low pressure (0-100mmHg) and a linear sensitivity region (20-400kPa) in the touch operation mode. Preliminary results show a sensitivity of 2.2fF/mmHg and are in good agreement with analytical and finite-element simulations.