Abstract: Space correction processing is performed for correcting an error between the position of actual space and the position of space which has been detected by a position sensor and can serve as a virtual space. Processing for setting the position of a screen is performed for accurately ascertaining the three-dimensional position of an image which is displayed on a screen. Processing for setting the position of a visual point is performed for setting the position of an actual visual point of an operator. Consequently, the position of the visual point and a position on the screen can be inputted accurately, and a highly accurate stereoscopic image is displayed in the virtual stereoscopic space faithfully to a real object by adopting the set screen position and the position of the visual point in the virtual space subjected to spatial correction.