Air-conditioning controlling system

An air-conditioning operation management company provides control information concerning air-conditioning equipments to a plurality of semiconductor manufacturing factories. The air-conditioning operation management company stores a measured result of an outside-air condition measuring unit in a past outside-air condition record database and obtains forecasted maximum temperature information on that day from a weather forecast providing system. An outside-air condition transition forecasting unit forecasts a transition of the outside-air condition on that day on the basis of the forecasted maximum temperature information. Information stored in an air-conditioning thermal load database, an air-conditioning equipment characteristic database and a set-temperature-and-humidity-of-air-conditioning-equipment database are employed to provide an optimum operation method of the air-conditioning equipments to the semiconductor manufacturing factories. Further, a forecasted result of an outside-air condition transition, an analyzed result of an air-conditioning thermal load and an analyzed result of a controlling method are displayed in customer terminals.