PROBLEM TO BE SOLVED : To easily grasp the understanding of an amount of tax reduction by the calculation of an amount of a fixed asset tax on remaining forest parts of a golf course by current state evaluation.SOLUTION : Drawing data showing the region of a golf course and a space photograph imaging the golf course from the sky are matched (ST2). Remaining forest parts of the golf course are extracted on the basis of the rough estimate of the area of the remaining forest parts, an amount of the fixed asset tax on the remaining forest parts is calculated by current state evaluation, and an amount of tax reduction from calculation by integral evaluation is calculated (ST3).