A coal-fired power plant having a control unit including a first flow rate control valve for regulating a water flow rate of a water feed bypass system, a second flow rate control valve installed in an extraction pipe for extracting steam from a steam turbine, a first temperature sensor on a downstream side of a heat recovery device, and a second temperature sensor on a downstream side of a heat exchanger and the control unit regulates opening of the first and second flow rate control valves on the basis of an exhaust gas temperature detected by the first temperature sensor and a feed water temperature detected by the second temperature sensor.Accordingly, even when a recovery heat quantity of the heat recovery device installed on a gas duct is changed due to deterioration with age of a boiler, a reduction in plant reliability and plant efficiency can be suppressed.