An image display device includes a display that displays at least one of a visible image of an object and a thermal image that represents temperature information of the object by a color and a control unit that controls the display. The control unit causes the display to display one of a first image and a second image. The first image includes the thermal image and the visible image. The second image does not include the visible image but includes a thermal image that is more enlarged as compared to the thermal image in the first image with a numerical value indicating a temperature being superimposed for each predetermined region on the thermal image in the second image.