AIRTIGHT TERMINAL

PROBLEM TO BE SOLVED: To solve such a problem that great stress due to the difference in thermal expansion coefficient occurs between an insulator and a conductor pin to cause cracks or check in the insulator. SOLUTION: This airtight terminal comprises the columnar insulator 1 having a through-hole in the axial direction, the conductor pin 2 inserted into the through-hole with both ends protruded therefrom, metal bonding members 3 for bonding the end face of the insulator 1 and the conductor pin 2 with air tightness, and a metal sleeve 4 to be bonded to the outer periphery of the insulator 1. At least one of the metal bonding members 3 has a cylindrical body 3b having a diameter smaller than that of the insulator 1 and larger than that of the conductor pin 2, a collar portion 3c integrally provided at one end of the body 3b to be bonded to the end face of the insulator 1, and a cylindrical portion 3d integrally provided at the other end of the body 3b via a step portion 3a, into which the conductor pin 2 is inserted and bonded.