A stereoscopic video image is observed by displaying to left and right display devices arranged in front of the left and right eyes of an observer, left and right images formed on an image pick-up device by using a stereoscopic optical system. Then, a read address of image data stored in a memory is changed by operating a display position adjusting pick or the like, thereby simply variably adjusting the display positions of the left and right images. As a consequence, it is possible to respond to the case in which a parallax of the observer is varied.