PURPOSE: To seal a metallic member stuck with a glass brazing material without causing thermal deformation of a mating member and any contamination around the sealed part by forcing the preceding end of the metallic member into the through-hole of the mating member to be sealed and melting the glass brazing material by heating.

CONSTITUTION: The preceding end of a metallic member 3 is inserted into a through-hole 2 and a glass brazing material 4a is heated with burners 5, 5. Thereafter the member 3 is pulled down and the red heated part of the member 3 is inserted into the well of the brazing material 4b. When the member 3 is pulled up, a part of the material 4b is pulled up while held stuck on the member 3 and is heated by the burners 5, 5. The vertical movement of the member 3 is repeated plural times and at every pulling the part stuck with the material 4b is heated. If the burners 5, 5 are stopped and the member is cooled, the material 4c assumes an ideal sectional shape and closes the hole 2. The member 3 is sealed to the mating member 1 by the material 4c and no deformations are generated in the member 1 at all.