To provide a differential pressure transmitter which will not reduce the resistance to pressure for differential pressure even when thermal strain on a block section is not permitted to be transmitted to a detection element, by increasing the thickness of adhesive which fixes the detection element and the block section.

The flexible detection element, having a sealed structure in between its one surface and the other surface, is mounted on the block section, and the detection element is deformed by the difference between the pressure applied to the one surface and that applied to the other surface. The deformation is converted into an electrical signal to be transmitted, and the detection element is attached to the block section via an O-ring and the adhesive.