To reduce the generation of stress due to the restraint of a diaphragm, and to ensure expected withstand pressure.

An inner edge L1 of a peripheral edge portion 11-6c of a holding member (a first holding member) 11-6 joined to one surface 11-1A of a sensor diaphragm 11-1, is positioned on the outer side than an inner edge L2 of a peripheral edge portion 11-3c of a stopper member (a second holding member) 11-3 joined on the other surface 11-1B of the sensor diaphragm 11-1. When measuring pressure Pa is made to be measuring pressure on a high-pressure side and measuring pressure Pb is made to be measuring pressure on a low-pressure side, if the measuring pressure Pa on the high-pressure side is applied on the one surface 11-1A of the sensor diaphragm 11-1, between the inner edge L1 (a diaphragm supporting point) of the peripheral edge portion 11-6c of the holding member 11-6 and the inner edge L2 (a pressure applying side supporting point) of the peripheral edge portion 11-3c of the stopper member 11-3, the sensor diaphragm 11-1 can be warped without generating excessive tensile stress due to restraint, so that stress generated at that part is reduced.