To provide an apparatus for reducing heat filled in a airplane especially in a super-sonic aircraft during flight for exhausting a part of heat incoming through the outer shell before reaching and heating the aircraft cabin and the fuel stored in the wings.

Air consumed for absorbing the heat incoming through the outer shell and for heating to the temperature level of the outer shell is guided from the cabin to the space between the outer shell and the cabin panel of the aircraft. A filter apparatus 11 is provided. Heated and consumed cabin air is supplied to the filter apparatus. At least one turbine 12 for expanding and cooling the cabin air is mounted behind the filter. Cooled and expanded air is guided through a hollow chamber 14 positioned between the lower surface of the wing 10 and the fuel tank 15 for absorbing and exhausting the heat incoming from the wing lower surface.