Abstract: There is described a method of drying air with the aid of a rotor (6) which rotates continuously in a housing (2) and which incorporates moisture-sorbent means. The housing (2) has mounted therein a casing (12) which is located on the low-pressure side of the rotor and provided with heat-emitting devices, for instance electrical elements (15), for delivering radiant heat directly to the rotor interior. The heat required for regeneration is therewith delivered at high temperature, which increases the heat yield. The part of the rotor (7) which is normally the most difficult to regenerate is therewith heated to a temperature of 250.degree.-300.degree. C. Since the volume of regeneration air is smaller than normal, the air is heated to a temperature which is much higher than normal in all parts of the rotor, so as to result in effective removal of the moisture present. The invention also relates to an air dryer by means of which the method can be put into effect.