An image scanning device includes: a main body that has a box-shaped appearance having a front face and a back face; a flat bed scanner unit that is mounted on the main body to be rotatable around an axis provided near the back face along a width direction of the main body; and a stopper that supports the flat bed scanner unit in an opened state. The stopper includes: a base end that is rotatably attached to an upper portion of the main body; and a leading end that is slidably attached to the flat bed scanner unit. A casing of the flat bed scanner is provided with a stopper accommodating portion that is recessed from a bottom surface of the casing. The stopper accommodating portion accommodates the stopper above the bottom surface in a closed state where the flat bed scanner unit is closed.