PURPOSE: To provide an improved mouse in which both pointing and scrolling can be simultaneously executed.

CONSTITUTION: A device (for example, a mouse) for controlling a cursor on a display device is provided with an auxiliary controller having a displaceable knob 41 mounted on one side face of a housing 19 for simultaneously operating both scrolling and pointing. The auxiliary controller generates an auxiliary control signal in response to the operation of the knob. This knob is designed so as to be operated by the thumb of a hand holding the mouse. A scrolling parameter is dynamically designed by detecting a preliminarily decided pattern in the orbit of the cursor, and simultaneously the mouse is operated. A scrolling direction is designed so as to be made correspond to a main axis present in the orbit. The design of various scrolling scales including the scrolling to a direction orthogonally crossing a screen plane can be attained by detecting an almost circular cursor motion.