The present invention provides a three-dimensional image display device for improving the visibility with prevention of moiré phenomena. The display device includes an image panel having a pixel repeatedly arranged in a first direction. The pixel consists of k sub-pixels where k is natural number. The average of the center distances between adjacent sub-pixels in the first direction is Psub. The display also includes a barrier panel arranged before or behind the image panel, a first substrate and a second substrate facing each other. The barrier panel is arranged between the first and the second substrate. The display device further includes a plurality of walls extended in a second direction crossing the first direction arranged with an interval Pw in the first direction, where m is a natural number but not a multiple of k, and Pw=mPsub.