Disclosed is a method for manufacturing a sealed contact point by injecting an arc extinguishing gas into an air-tight space of an electromagnetic switching device and sealing it. The method includes forming a driving body and coupling a housing and a plate to form an air-tight space, air-tightly fixing a detachable chamber forming the interior of the chamber under an insulating gas atmosphere, inserting the protruded shaft and core of the driving body into the cylinder and coupling the cylinder to the lower portion of the plate to form a sealing structure, and sealing the plate and the cylinder.