A pressure sensor chip according to the present invention includes a non-bonding region that is provided in a stopper member and connected to a periphery of a pressure introduction hole. A plurality of protrusions are discretely formed on at least one of a first surface and a second surface that face each other in the non-bonding region. Passages between the protrusions serve as channels between the periphery of the pressure introduction hole and a peripheral edge of the non-bonding region. Accordingly, stress concentration does not occur at a diaphragm edge and the expected withstand pressure can be obtained.