Abstract: The CO2 capture system by chemical absorption for removing CO2 from a combustion exhaust gas by a solvent, comprising: an absorber for absorbing CO2 by a solvent, a regenerator for heating a rich solvent absorbed CO2 thereby releasing CO2, a gas exhaust system for discharging gas from the regenerator, a gas compressor installed in the gas exhaust system, a heat exchanger disposed downstream of the gas compressor for exchanging heat between compressed gas and rich solvent to be supplied to the regenerator, a gas-liquid separator disposed downstream of the heat exchanger for separating gas from condensed water, a condensed water supply system for supplying condensed water from the gas-liquid separator to the regenerator, another gas exhaust system for discharging gas containing high-concentration CO2 from the gas-liquid separator, and a compressor disposed downstream of the gas-liquid separator in the another gas exhaust system for pressurizing the gas containing high-concentration CO2.