PURPOSE: To attain the input of plural continuous quantities in addition to the input of a two-dimensional moving amount without moving an input device for the continuos quantities by showing the detected continuous quantities on a display screen.

CONSTITUTION: Another ball 8 is set at the lower part of a mechanical mouse device to measure the rotation amount of the mouse device. That is, a main ball 7 measures the two-dimensional moving amount of the mouse device and the ball 8 measures the rotational amount and the horizontal moving amount of the mouse device respectively. Then the rotary encoders 9, 10 and 11 measure the vertical moving amount, the horizontal moving amount, and the rotational amount and the horizontal moving amount, of the mouse device respectively. When a prescribed processing is applied, the two-dimensional moving amount of the mouse device is equal to 0 by the rotation of the mouse device even in a continuous quantity input state. Therefore a mouse cursor shown on a bit map display never has the flickering movements.