A silicon resonant type pressure sensor has a sensing diaphragm to which a measuring pressure is to be applied; and a vibrating beam which is embedded on the sensing diaphragm, and which is made of a semiconductor, wherein the vibrating beam further has a vibrating beam body having first and second vibrating beams which are allocated in parallel each other, and at least one connecting beam portion which couples the first vibrating beam and the second vibrating beam, a driving vibrating beam portion which is fabricated on a side of at least one side face in an axial direction of the first and second vibrating beams, and which is made of a conductor, and detection vibrating beam portions which are fabricated on sides of another side face in the axial direction of the first and second vibrating beams respectively, and which are made of a conductor.