An induction heating coil (3) has a primary coil (4) to which electric power is supplied and a ring-shaped secondary coil (5) forming a closed circuit. The primary coil (4) has a base-side portion that covers an outer periphery of the secondary coil (5) and a distal-side portion extending from the base-side portion in the center axis direction of the secondary coil (5) in a state in which the base-side portion covers the secondary coil (5). The opening width of the base-side portion is greater than the opening width of the distal-side portion. The secondary coil (5) is provided such that it can be inserted into and removed from the inside of the primary coil (4) from the base-side portion of the primary coil (4).
