Parallax images corresponding to a plurality of different view points are each divided into predetermined stripe images, a synthetic parallax image is synthesized from the stripe images, and display light, from stripe images corresponding to one view point of the synthetic parallax image on the image display element displaying the synthetic parallax image, is guided to a mask member having a mask pattern with predetermined openings and shields by a second optical system placed in front of the image display element. The display light passing through the openings of the mask member is condensed to a position corresponding to the view point on an observation surface a predetermined distance apart, by a first optical system, whereby an observer is permitted to stereoscopically observe image information displayed on the image display element.