It is an object of the invention to provide a display device which performs high grayscale display in accordance with display contents and a game machine with an improved realistic sensation. The invention is a display device characterized by including a pixel portion which performs display based on a video signal and a driver circuit portion inputted with the video signal, wherein the driver circuit portion has a unit for controlling a grayscale in accordance with display of the pixel portion. In a liquid crystal display device, luminance of a lighting unit is controlled based on a signal from the unit for controlling a grayscale whereas a current supplied to a light emitting element is controlled in a light emitting device. By applying such a display device to a game machine, a realistic sensation can be improved.