A power-generating plant comprising: a steam turbine system comprising a steam turbine (3, 8); a boiler adapted to allow water and combustion gas (66, 90) to undergo heat exchange to generate water vapor driving the steam turbine (3,8); absorption equipment adapted to allow absorbing liquid to absorb carbon dioxide in exhaust gas from the boiler; regeneration equipment adapted to separate carbon dioxide from the absorbing liquid having absorbed carbon dioxide in the absorption equipment; an economizer, installed in the boiler, adapted to allow water and combustion gas (66, 90) to undergo heat exchange to preheat the water serving as working fluid of the steam turbine (3, 8); an air preheater installed downstream of the economizer and allowing combustion air and combustion gas to undergo heat exchange to heat the combustion air; and an exhaust gas pipe allowing the air preheater and the absorption equipment to connect with each other, characterized in that the power-generating plant further comprises: first steam generating means (5, 6), installed downstream of the economizer, for allowing water, the water utilized in the steam turbine (3,8) as working fluid, and combustion gas to undergo heat exchange to generate saturated water vapor; second steam generating means for allowing the saturated water vapor from the first steam generating means (5, 6) and absorbing liquid from the regeneration equipment to undergo heat exchange to evaporate the absorbing liquid; a steam pipe allowing the first steam generating means (5, 6) and the second steam generating means to connect with each other; a steam bypass pipe connected to the steam pipe and adapted to allow the steam in the steam pipe to flow into a condenser of the steam turbine system; means, installed in the steam bypass pipe, for opening and blocking flow of the saturated water vapor in the steam bypass pipe; an exhaust gas bypass pipe connected to the exhaust gas pipe; and means, installed in the exhaust gas bypass pipe, for opening and blocking flow of the exhaust gas in the exhaust gas bypass pipe. a steam turbine system comprising a steam turbine (3, 8); a boiler adapted to allow water and combustion gas (66, 90) to undergo heat exchange to generate water vapor driving the steam turbine (3,8); absorption equipment adapted to allow absorbing liquid to absorb carbon dioxide in exhaust gas from the boiler; regeneration equipment adapted to separate carbon dioxide from the absorbing liquid having absorbed carbon dioxide in the absorption equipment; an economizer, installed in the boiler, adapted to allow water and combustion gas (66, 90) to undergo heat exchange to preheat the water serving as working fluid of the steam turbine (3, 8); an air preheater installed downstream of the economizer and allowing combustion air and combustion gas to undergo heat exchange to heat the combustion air; and an exhaust gas pipe allowing the air preheater and the absorption equipment to connect with each other, characterized in that the power-generating plant further comprises: first steam generating means (5, 6), installed downstream of the economizer, for allowing water, the water utilized in the steam turbine (3,8) as working fluid, and combustion gas to undergo heat exchange to generate saturated water vapor; second steam generating means for allowing the saturated water vapor from the first steam generating means (5, 6) and absorbing liquid from the regeneration equipment to undergo heat exchange to evaporate the absorbing liquid; a steam pipe allowing the first steam generating means (5, 6) and the second steam generating means to connect with each other; a steam bypass pipe connected to the steam pipe and adapted to allow the steam in the steam pipe to flow into a condenser of the steam turbine system; means, installed in the steam bypass pipe, for opening and blocking flow of the saturated water vapor in the steam bypass pipe; an exhaust gas bypass pipe connected to the exhaust gas pipe; and means, installed in the exhaust gas bypass pipe, for opening and blocking flow of the exhaust gas in the exhaust gas bypass pipe. first steam generating means (5, 6), installed downstream of the economizer, for allowing water, the water utilized in the steam turbine (3,8) as working fluid, and combustion gas to undergo heat exchange to generate saturated water vapor; second steam generating means for allowing the saturated water vapor from the first steam generating means (5, 6) and absorbing liquid from the regeneration equipment to undergo heat exchange to evaporate the absorbing liquid; a steam pipe allowing the first steam generating means (5, 6) and the second steam generating means to connect with each other; a steam bypass pipe connected to the steam pipe and adapted to allow the steam in the steam pipe to flow into a condenser of the steam turbine system; means, installed in the steam bypass pipe, for opening and blocking flow of the saturated water vapor in the steam bypass pipe; an exhaust gas bypass pipe connected to the exhaust gas pipe; and means, installed in the exhaust gas bypass pipe, for opening and blocking flow of the exhaust gas in the exhaust gas bypass pipe.