An image heating apparatus includes a coil for generating a magnetic flux; an endless belt having an electroconductive layer for generating heat by the magnetic flux of the coil wherein a recording material carrying image is heated by heat of the belt; a magnetic flux detecting means disposed opposed to the coil with the belt interposed therebetween and capable of detecting the magnetic flux from the coil, the magnetic flux detecting means including a detection portion capable of detecting such a part of the magnetic flux of the magnetic flux generated by the coil as is from a region corresponding to not less than one half of a heat generating region of the belt with respect to a widthwise direction of the recording material; and prohibition means for prohibiting electric power supply to the coil when an amount of the magnetic flux detected by the magnetic flux detecting means reaches a predetermined amount.