A liquid crystal display device including polarizing films that polarize infrared-range light as well as visible-range light and being operated in a visible light mode and an infrared light mode is disclosed. The liquid crystal display device includes a liquid crystal panel, polarizing films attached to the top and bottom surfaces of the liquid crystal panel, and a backlight unit disposed under the liquid crystal panel. At least one of the polarizing films includes an infrared polarizing film or a polarizing film for both visible and infrared light.