An image display device according to the embodiment includes a display screen, an operation input unit, a control unit, and a notification unit. The display screen displays an image using a display mechanism in which scanning can be optically performed in a copy machine. The operation input unit is arranged at a position of being operated in a state in which a display screen is placed on a glass original document table so as to face the glass original document table of a copy machine, and receives an operation input of a user. When a plurality of images are set to display targets in the display screen, the control unit switches an image displayed on the display screen according to the operation input of a user with respect to the input operation unit. The notification unit notifies of switching of an image when the image displayed on the display screen is switched.