A semiconductor pressure transducer for detecting a pressure applied to a diaphragm. The pressure transducer comprises a diaphragm and a pressure detector including an Si single crystal which is so formed as to have a crystal face of {110 } as the surface to which a compression force is applied, and which is attached to the pressure detector such that the crystal face is parallel to the diaphragm, a first pair of opposing electrodes provided on the Si single crystal in the direction having an angle of 45 degrees with the direction of on the crystal face of {110 } and a second pair of opposing electrodes provided on the Si single crystal in the direction having an angle of 45 degrees with the direction of of the Si single crystal, either of the first or second pair of electrodes serving as output electrodes and the other pair serving as input electrodes and composite seat with one end thereof bonded to the crystal face of {110 } of the Si single crystal so as to transmit the pressure applied to the diaphragm perpendicularly to the crystal face of the Si single crystal as a compression force. The pressure applied to the diaphragm acts perpendicularly to the crystal face of the Si single crystal as a compression force and the output electrodes output a voltage corresponding to the compression force.