Abstract: This invention provides a stereoscopic display apparatus which can discriminate image signals for the right and left eyes and can normally display an image without adding any special signals for discriminating the image signals for the right and left eyes. The basic principle of a stereoscopic display apparatus according to an embodiment of this invention will be described below with reference to FIGS. 2B and 2C. When the optical axes 210 and 211 of the photographing lenses are set to be parallel to each other, the position of the object image 201l in the field frame 212 is near the left end, and the position of the object image 201 in the field frame 213 is near the right end. In order to detect a relative positional relationship, in the right-and-left direction, of the object on the basis of the signal waveforms shown in FIG.