PURPOSE: To prevent deterioration of critical current of superconductive wire, on the occasion of exposing an conductor to two kinds of ambients when it is placed through the partitioning wall, by using a superconductive wire as a conductor provided therethrough and hermetically sealing the area through which the superconductor is placed with the brazing at a temperature as low as 400°C or less.

CONSTITUTION: A conductor 12 consisting of superconductive wire is placed through a partitioning wall 5 and is exposed to different ambients 3 and 4 through the wall 5. In this case, the passing area is hermetically sealed by a low temperature brazing at a temperature of 400°C or less. In this case, an alloy mainly consisting of tin and lead is used as the brazing material and a superconductive magnet having the conductor passing area which prevents critical current of superconductive wire and has no resistance loss can be obtained.