An image display device includes a display panel, a space portion, an illuminator, a controller, and an illuminance sensor. The display panel is switchable between an image display mode in which an image is displayed and a transmissive mode in which the display panel is in a transmissive state where a back side of the display panel is visible in a front view. The space portion and the illuminator are provided behind the display panel. The illuminator emits illumination light to the space portion. The controller controls the illuminator. The illuminance sensor detects an ambient illuminance of the image display device. The controller performs illumination control for causing the illuminator to emit illumination light with a brightness that is in accordance with a result of detection by the illuminance sensor when the display panel is operating in the transmissive mode.