The invention relates to a pole part for high pressure environment application, with a pressure resistant insulating housing in which a vacuum interrupter is installed, wherein the vacuum interrupter is provided with at least one moving contact and one fixed contact inside the vacuum interrupter, according to the preamble of claim 1. In order to create a pole part with high environmental pressure withstand, the invention is that the pressure resistant insulating body is tubelike and at its ends provided with flanges formed at the insulating housing out of the same material, and that at least one of the flanges is closed with a metal cap, which is adapted to the aforesaid flange of the insulating housing by the same dimensions, and that with clamping means the metal cap is pressed tightly on the flange of the insulating housing by the introduced clamping fixation force.