A CO2 recovery system includes an absorber 2 and a regenerator 3. The absorber 2 includes a CO2 absorbing section 21 and a water-washing section 22. The CO2 absorbing section 21 allows flue gas 101 to come into contact with a basic amine compound absorbent 103 so that the basic amine compound absorbent 103 absorbs CO2 in the flue gas 101. The water-washing section 22 allows the decarbonated flue gas 101A in which the amount of CO2 has been reduced in the CO2 absorbing section 21 to come into contact with circulating wash water 104 and to be washed with the wash water 104 so that the amounts of the basic amine compounds entrained in the decarbonated flue gas 101A are reduced. The regenerator 3 releases CO2 from the basic amine compound absorbent 103 the CO2 absorbed therein.