Synthesis gas (syngas) gasified in a gasification furnace to which coal is introduced burns in a combustor. An exhaust-heat recovery boiler generates steam by using exhaust gas let out from a gas turbine equipped with the combustor. The steam generated in the exhaust-heat recovery boiler is introduced to a steam turbine. A generator is driven by the steam turbine and the gas turbine to generate electrical power. Part of the exhaust gas let out from the gas turbine is introduced to a carbon-dioxide recovery unit, where carbon dioxide is recovered therefrom. Coal is carried to the gasification furnace by the carbon dioxide.