A control server includes a device information database storing device characteristic data constituting the air conditioning equipment, a fuel/power rate database storing price and rate data regarding gas, oil, power and the like, a device characteristic and price database, an air conditioning equipment simulator for calculating running costs by using the data stored in the fuel/power rate database, and communication portion for performing communications through a network. The control server, and an air conditioning management controller for managing and controlling the air conditioning equipment provided with the communication portion for performing communications through the network, are connected to the network. An operation plan is made by the control server, the operation plan is transmitted to the air conditioning equipment management controller for controlling the air conditioning equipment through the network, and the air conditioning equipment is controlled and operated according to the operation plan.