[PROBLEMS] To quantize the effect obtained by a communication company by providing a non-sensitive area countermeasure and effectively identify the location where the countermeasure should be taken at early stage. [MEANS FOR SOLVING PROBLEMS] A non-sensitive building is extracted according to radio environment data indicating the current condition of the radio communication environment in the search target area and digital map data including attribute information concerning the buildings in the search target area, thereby acquiring attribute information corresponding to the non-sensitive building. The known use condition data on target radio communication system or the similar system and the digital map data are used to obtain an equation for estimating the affect given to the effect of benefits by the attribute information parameter. According to the extracted non-sensitive building attribute information and the obtained equation, the effect obtained by performing the non-sensitive area countermeasure to each of the non-sensitive buildings is estimated. The priority of performing the non-sensitive area countermeasure is decided in accordance with the effect scale.