PURPOSE: To simplify the structure by interposing an insulation member having a through hole for lead between a differential pressure detecting part and a dielectric sealing part for passing the lead provided at the outer circumferential part of the main body of a differential pressure detector incorporating the differential pressure detecting part.

CONSTITUTION: A lead 2 penetrates a dielectric sealing part, i.e., a hermetic seal terminal 3, and passes through a hole of an insulating member 4 to come into pressure contact, at the tip thereof, with each electrode at a differential pressure detecting part 1 thus deriving a detection signal. Since the deburring work, requiring the drilling work of an insulation pipe or a special work such as electrolytic polishing, is limited to only one hole of the insulating member, machining cost is reduced and since an inexpensive insulation material is employed, the material cost can also be reduced.