The position and orientation of an input device body (52) in the actual space are sensed. The manipulated variable of an operating member (56), which is present in the actual space so as to be operated without changing the position and orientation of the input device body (52), is sensed. A pointing image (80) is generated on a screen (70) according to the position and orientation of the input device body (52) and the manipulated variable of the operating member (56). The point indicated by the pointing image (80) on the screen (70) is changed according to the change of the position and orientation of the input device body (52) and the change of the manipulated variable of the operating member (56).