Provided is a highly reliable liquid crystal display device that prevents the penetration of a flying dust and dirt in the outside air. A liquid crystal display device (1) having a display unit housing case (2) configured to house a light source unit and a display unit, and an electronic component housing case (3) configured to house an electronic component. The liquid crystal display device (1) is tightly closed and externally disposed with heat radiation fins (6a and 6b).