An image generating device for forming a behind object prepared with polygon data as a part of the background of a virtual three-dimensional space and generating images of the movement of a character object prepared with polygon data in this virtual three-dimensional space. A visual field seen from a viewpoint is operated, and behind objects OTa, OTb, and OTc positioned within this visual field and observable from the viewpoint are specified. Moreover, judged is whether it is the specific condition wherein the character object OTch is within the visual field and positioned in the space closer to the viewpoint side than the specified behind object. The character object OTch is incorporated as the object of display only when it is judged as being this specific condition.