An image heating device with a small thermal capacity that can be heated rapidly. The image heating device includes a fixing belt (20) having a heat resistance; a rotatable heat-generating roller (21), which is at least partially conductive and arranged in contact with an inner peripheral surface of the fixing belt (20); a fixing roller (22), the fixing roller and the heat-generating roller (21) movably suspending the fixing belt (20) therebetween; and a magnetization means (24) for heating the heat-generating roller (21) through magnetization, which is arranged outside the heat-generating roller (21). In this image heating device, the magnetization means (24) heats the heat-generating roller (21) through magnetization after a rotating operation of the heat-generating roller (21) is started.