PURPOSE: To generate easily a stereoscopic video image to be moved freely by turning a spiral step form screen to move the screen, and utilizing a 3-dimensional space made by the movement to generate a stereoscopic video image.

CONSTITUTION: An electron ray radiating device 2 irradiates an electron ray while moving it freely vertically and horizontally. In turning the screen 1 by a motor 3, the screen 1 is moved to all parts except a shaft 7 in a cylindrical space taking the length in the turning direction as the radius and the axial length as the height. An optional point P in the optional space in a cylinder taking the length for spiral 360° at the side of the electron ray radiating device as the height is lighted. When the screen 1 in movement comes to a position including the point P, the electron ray radiating device 2 irradiates the electron ray momentarily toward the point P and the electron ray is emitted to irradiate the screen 1 on the point P so as to light the screen 1.