A pressure sensor includes a semiconductor substrate and a pedestal member such as a glass pedestal. The semiconductor substrate has a diaphragm for detecting a pressure and a thick portion positioned around the diaphragm. The pedestal member has one surface bonded to the thick portion of the semiconductor substrate and the other surface opposite to the one surface. In the pressure sensor, the pedestal member has a through hole through which pressure is introduced to the diaphragm. The through hole penetrates through the pedestal member from an opening of the other surface to the one surface of the pedestal member, and the through hole has a hole diameter that becomes smaller from the one surface toward the other surface of the pedestal member. Accordingly, it can effectively restrict foreign materials such as dusts from being introduced into the through hole of the pressure sensor.