To provide a castable fire resistant material fitting method capable of preventing a fall of the castable fire resistant material fitted to the inside of an induction heating coil to protect the induction heating coil and an insulating material provided in a surface of the induction heating coil from the heat.

A glass tape ribbon 8 is stretched from an upper end to a lower end in a cylindrical clearance 9 between the induction heating coil 7 and a framework 6 to be filled wit the castable fire resistant material 2, and the ribbon 8 is fixed at both ends of the induction heating coil 7. Twenty-four glass tape ribbons 8 are arranged for fixation so that the glass tape ribbons 8 are embedded in the circumference of the castable fire resistant material 2 with a nearly equal space, and the castable fire resistant material 2 is filled for solidification in the cylindrical clearance between the induction heating coil 7 and the framework 6, and thereafter, the framework 6 is removed to obtain the induction heating coil with a fire resistant material for the induction heating device.