HEATING DEVICE, FIXING DEVICE, AND IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To provide a heating device capable of providing uniformity in temperature in a longitudinal direction of a fixing member.SOLUTION: A heating device 45 employing an induction heating system includes: an excitation coil 61 that is arranged opposite to an outer peripheral surface of a fixing member 41 provided with a heating layer, and generates a magnetic flux; at least one type of magnetic body core 64 that forms a magnetic path to introduce the magnetic flux generated by the excitation coil to the fixing member; and a holding member 65 that holds the excitation coil and the magnetic body core. The magnetic body core 64 has a thickness in end parts formed smaller than that in the center part.