A semiconductor pressure sensor chip is housed in a pressure detecting chamber, and a pressure port is provided which causes the pressure detecting chamber and a space in which pressure is to be measured are in communication with each other. A protective portion is provided inside the pressure port in such a manner as to substantially close an inlet of the pressure detecting chamber in the state in which the pressure detecting chamber and the space in which pressure is to be measured are in communication with each other. This prevents degraded and solidified foreign matter such as oil and gasoline, which are led into the pressure port from the space in which pressure is to be measured, from entering the pressure detecting chamber and colliding with the sensor element and the like.