A plurality of thermal power generation plants 100 are provided with a communication terminal 200 and a function of controlling respectively a boiler control unit 110, a turbine control unit 120 and an auxiliary machine sequence control unit 130 based on an operation signal inputted via the communication terminal 200. A remote control center 10 which is connected to the communication terminal 200 via the Internet 300, accesses the control units and remotely controls operating states including starting and stopping of the concerned thermal power generation plant 100.