To prevent lowering of sensor characteristic by eliminating the need for formation of a protection film in a pressure surface of a diaphragm in a semiconductor pressure sensor with a diaphragm.

An inside of a semiconductor board 1 of a semiconductor pressure sensor 100 has a standard pressure chamber 2 and a part at a side of rather one surface 1a than the standard pressure chamber 2 of the semiconductor board 1 is constituted as a diaphragm 3 for pressure receiving. A pressure sensing element 4 for generating an electric signal based on strain of the diaphragm 3 is formed in a surface at the side of the reference pressure chamber 2 of the diaphragm 3 and in the pressure sensing element 4, a signal can be picked up to the one surface 1a of the semiconductor board 1 by a conductor 5 formed inside the semiconductor board 1.