An image heating apparatus includes: a first heater, having a nip through which a sheet passes, for heating toner image on the sheet; a second heater, having a nip through which the sheet passes, capable of heating the toner image on the sheet having passed through the first heater; a changer for changing the feeding speed of the sheet of the second image heater; two detectors for detecting the amount of slack of the sheet at one and the other ends of the sheet when the sheet is nipped by both of the nips; an adjuster adjusting the distance between the first and second heaters at the one and the other ends; and a portion for executing a correction mode when the amounts of slack detected by the detectors are different from each other, so that after the adjuster reduces the distance, the feeding speed is controlled.