Inductor for heating inner-circumference of hole

1. Field of the Invention There is provided an inductor for heating the inner circumference of a hole, by which induction heating of the inner circumference of a hole and so on can be realized rapidly and uniformly in the direction of the circumference, and there is no risk of a short-circuit between a solenoidal coil and transition conductor passing therethrough. According to a configuration in which a magnetic core with a cylindrical shape is arranged inside of a solenoidal coil which forms the inductor , and a transition conductor extending from one end of the solenoidal coil to a feeding terminal through the inside of the solenoidal coil is arranged in an inserted manner into a hollow portion of the magnetic core , a risk of the short circuit is avoided by using an insulating material for the magnetic core , assuming that the magnetic core with a large cross-sectional area is concentrically arranged in the solenoidal coil