Copper‐supported activated carbon (Cu‐SAC) was studied for the simultaneous removal of SO2, NO, and CO2 in different operating conditions. The effects of Cu loading, adsorption temperature, O2 concentration, and relative humidity (RH) were studied. The experimental results showed that Cu‐SAC containing 9.8% of Cu had the best removal activity of SO2, NO, and CO2. The activity dropped with the further increase of Cu loading. Higher temperatures were not in favor of simultaneous adsorption of SO2, NO, and CO2. The performances of the removal of SO2 and NO improved obviously in the presence of O2. Water vapor could improve the adsorption performance of SO2, but higher RH was bad for the adsorption performance of SO2. The adsorption of NO and CO2 was deterred in the presence of water vapor. Cu‐SAC was shown to be a potential sorbent for simultaneous adsorption of SO2, NO, and CO2. © 2015 American Institute of Chemical Engineers Environ Prog, 34: 1044–1049, 2015