A cogeneration system (100) of the present invention comprises a SOFC (13) configured to generate electric power through a power generation reaction by using a fuel gas supplied to the fuel cell and air supplied to the fuel cell; a reformer (16) configured to generate a reformed gas by utilizing power generation reaction heat and combustion heat; a vaporizer (15) configured to generate the steam to be added to the fuel gas supplied to the reformer (16) by utilizing the power generation reaction heat and the combustion heat; an ammonia absorption chiller (10) configured to cool a target by consuming a portion of the power generation reaction heat and a portion of heat of an exhaust gas having the combustion heat which remain after the reformer (16) and the vaporizer (15) have consumed the heat, and cool the exhaust gas by consuming the portion of the heat; and a condensation unit (30) configured to cool the exhaust gas after the ammonia absorption chiller (10) has consumed the portion of the heat owned by the exhaust gas, to condense a moisture contained in the exhaust gas to generate condensed water.