A stereo image display device includes an image display unit for displaying a parallactic image having a right-eye image and a left-eye image on a display plane, a parallactic image selecting unit for making only the right-eye image of the parallactic image reach the right eye of a viewer and making only the left-eye image of the parallactic image reach the left eye of the viewer to thereby make the viewer view a stereo image, an eye fatigue degree detecting unit for detecting the eye fatigue degree of the viewer, and an eye fatigue relaxation processing unit for carrying out eye fatigue relaxation processing for relaxing the eye fatigue of the viewer.