A guide display device which is installed in a predetermined direction includes: a first screen which is parallel to the predetermined direction; a first light source which illuminates the first screen; a cover which is provided above the first screen in the predetermined direction and projects in a direction crossing the first screen to block light from above the guide display device and cast a shadow upon an area of the guide display device; a second light source which illuminates the area on which the shadow is cast; and a controller which causes at least the second light source to perform optical communication.