Abstract: The invention relates to auxiliary systems ensuring functioning of alkaline fuel cell (AFC), in particular to a method and device for sorptive purification of air used in an AFC of carbon dioxide. In accordance with the invention, in the method for purifying air for a fuel cell, the starting air is passed through an adsorber with an adsorbent of carbon dioxide, then the adsorbent is regenerated. After utilization the adsorbent comprising hydrated oxides of transition metals is regenerated at a temperature of 60-120° C. by the air spent in the fuel cell. The air fed for regeneration is heated until a relative humidity of from 15 to 85% is achieved.