An erasing device of one embodiment includes a conveyance unit that conveys a sheet; a pair of rotating brushes is provided corresponding to both side portions in a width direction perpendicular to a sheet conveyance direction of the sheet conveyed by the conveyance unit, the rotating brushes being provided to oppose to each other, nipping the conveyed sheet, the rotating brushes rotating in the same direction as the sheet conveyance direction such that a circumferential speed of the brush tip has a higher speed than a conveyance speed of the sheet, the rotating brushes rolling and correcting a corner fold portion which occurs on the sheet conveyed by the brush tip portion while rotating; and an erasing unit is provided downstream in the sheet conveyance direction than the rotating brush, the erasing unit erasing an image which is formed on the sheet.