The 3D image display device disclosed herein includes an image display panel outputting image signals; and a parallax barrier arranged in front of the panel, being spaced at a particular distance, and having a plurality of transparent portions. The transparent portions of the barrier have a plurality of transverse lines, each of which forms one cycle, and the transparent portions that are adjacent to each other in the longitudinal direction in one cycle are arranged to emit images to different fields of view, respectively. The panel operates on and off by lines in the transverse direction based on views.