Abstract: A differential pressure gauge comprises a balance beam (3) acting upon a vibrating blade (6). The beam (3) and the blade (6) are disposed in a rigid chamber 4 under vacuum. The beam (3) is acted upon by a force, resulting from the deformation of a flexible or expansible chamber (7) subjected to a pressure P.sub.T and disposed in a second rigid chamber (5) subjected to a pressure P.sub.S. A flexible or expansible seal element (9) isolates the chambers but transmits the forces without disturbing them. This gauge has a high precision and delivers information in digital form, particularly useful in aeronautics.