An image erasing apparatus includes: a scanner which detects a side of a sheet on which an image is formed using a thermally decolorable coloring agent; a heat roller which provides heat for the sheet having the image formed thereon; and a controller which causes a quantity of heat provided for the sheet from the heat roller when an image forming side detected by the scanner does not face the heat roller to be greater than a quantity of heat provided for the sheet from the heat roller when the image forming side faces the heat roller.