To easily acquire three-dimensional shape information (height information with continuity) of an optional object in a real space to which a viewer belongs with less calculation quantity and to control an image of a virtual body synthesized on a reference plane in the virtual image on the basis of the three-dimensional virtual shape information.

The virtual image stereoscopic synthesis device is provided with a bracelet 1 with a reference plane setting function for acquiring a three-dimensional shape to recognize an optional reference plane in a real space to which a viewer belongs, a special Glasstron (registered trademark) 2 that synthesizes images of a 3D polygon 10 on a reference plane of a virtual space as if the 3D polygon 10 were in existence at a position in a real space to which the reference plane belongs, and three-dimensional shape acquisition device 6 that acquires a three-dimensional shape of an object 30, synthesized at a porition including the 3D polygon in the vitual space, such as a right hand of the viewer placed at a position parted from the reference plane in the real space, and the image is processed so that the image of the 3D polygon is changed in the virtual space on the basis of the three-dimensional shape information obtained from the three-dimensional shape acquisition device 6.