To provide a small and low-cost induction heating device, in realizing an inexpensive heating coil which is cooled easily.

In the heating coil for the induction heating device, the inner peripheral part of a spiral electrical conductor 8 is made closer to of farther from a heated material than the other parts of the spiral electrical conductor, and the cooling wind can especially easily reach the inner peripheral part, with the inner peripheral part can be cooled effectively.