A method for extinguishing fire, wherein a gas an aerosol mixture is fed into a space includes steps of igniting a pyrotechnic composition that ensures a predetermined temperature profile during burning and a predetermined composition of the gas and aerosol mixture completely oxidizing the combustion products of incomplete combustion of the pyrotechnic composition by causing them to pass through a bed of catalytically active substances, which is located in the zone of the maximum temperature of the temperature profile of combustion of the pyrotechnic composition, with the temperature remaining constant by redistribution of said profile; cooling the combustion products and completely oxidizing them by reacting with substances having high heat absorbing capacity, concurrently with the filtering of the combustion products according to composition of the gas phase and particle size of the aerosol phase. An apparatus for extinguishing fire, having a casing (1) that has a discharge port (2), a combustion chamber (3) that is accommodated in the casing (1) and heat insulated from the walls of the casing (1), a pyrotechnic composition (4) and an igniter (5) that are received in the combustion chamber, a cooling section (9) and a complete catalytic oxidation section (6) that has a pair of spaced metal gratings (8a, 8b) between which a catalytically active substance is placed and that is located at a fixed distance from the pyrotechnic composition (4). A compensation device (10) is provided for maintaining the above-mentioned fixed distance during the burning of the pyrotechnic composition (4).