A CO2 recovery method and apparatus for desorbing and recovering carbon dioxide with low energy consumption from a gas discharged from a power generation plant having a boiler and a steam turbine. The adsorption and the desorption of carbon dioxide are performed alternately in two CO2 absorbers and located in a CO2 recovery apparatus, which each hold a carbon dioxide adsorbent. When carbon dioxide is desorbed, steam discharged from an outlet of a steam turbine of a power generation plant is partially branched before introduced into a condenser, and sent to a steam compressor. The partially branched steam is compressed in this compressor, and then sent to a cooling device. By cooling, the steam for desorption is prepared. The steam prepared in the cooling device is supplied into a CO2 absorber to desorb carbon dioxide. Accordingly, waste steam, before it is introduced into the condenser, is usable for desorption.