PURPOSE: To obtain sufficient long-period security against fine vacuum leakage by evacuating a gap between a diaphragm and a base supporting part and a can part which covers a through hole for evacuation formed at the base supporting part externally.

CONSTITUTION: The metallic can part 6 is arranged under (outside) the through hole 7 for evacuation formed at the base supporting part 2 while covering the through hole 7 and the periphery 6a of the metallic can part 6 is fixed to the base supporting part 2. The can part 6 is evacuated through an air hole 8 formed at its lower end and sealed under a vacuum by soldering 9 to hold the gap between the electrodes 4 and 5 of the detecting elemenet part of an electrostatic capacity type pressure sensor and the metallic can part 6 under a vacuum. A lead line 10 is connected to a detecting circuit which is not shown in a figure. This structure increases the volume in the vacuum state and even if fine air leakage occurs to the electrostatic capacity type pressure sensor, its security period is extended.