To provide an airtightly sealed power supplying part capable of supplying a big current of several 10 A with a simple manufacturing method.

For a metal lead wire 2 with a thermal coefficient of linear expansion of 35 to 55×10-7 (cm/cm/°C) at 500°C, and a heat resistant tube 1 sealing the inserted metal lead wire 2 at its end parts, the heat resistant tube 1 has a slanted function part, where, the thermal coefficient of expansion changes continuously through a sealed side 1a and an opened side 1b.