PURPOSE: To assure the stable joining for the purpose of optical joining extremely accurately in terminal parts by depositing a magnetic metallic layer on the outside circumferential end parts of stationary and movable optical fibers, forming the opposite placing parts of both fibers as V-shaped grooves, and disposing electromagnets in said grooves.

CONSTITUTION: Stationary optical fibers 46W49 are disposed at the intermediate of the V-shaped grooves 42W45 formed to a hollow cylindrical holder 40, and a movable optical fiber 51 is fixed and disposed in opposition to the end part of the stationary fiber 46 in a curved state in a manner as to make optical connection by placing its end part on the V-groove 42. Electromagnets 54W57 are buried from the outside circumference of the holder 40 toward the V grooves 42W45, and the magnetic pole magnetic bodies 58W61 thereof are secured across the stationary and movable optical fibers at close distances from the V grooves or in connection to the fibers 46W49. These magnetic poles 58W61 are all formed of permanent magnets or magnetic materials holding suitable residual magnetic force. Thereby, the extremely stable joining in the terminal parts is accomplished.