PURPOSE: To improve the work efficiency by preparing plural kinds of moving functions for calculating a moving amount of a cursor, and using them selectively in accordance with a variation of a moving state of a pointing device.

CONSTITUTION: Plural kinds of moving functions for calculating a moving amount of a cursor from a moving amount = (Δx, Δy) and a moving time Δt given to a pointing device 1 are prepared in an arithmetic part 9, and used selectively in a variation of a moving state of the pointing device 1. In such a way, even in the case the moving amount of the cursor on a screen is large, the moving amount of the pointing device 1 can be suppressed small by varying correctly a moving state of the pointing device 1, and the work efficiency can be improved and the operator's burden can be reduced.