To provide a float type carburetor for a four cycle or two cycle internal combustion engine which is improved in prevention fuel leakage and fuel clogging caused by malfunction of a float and a needle valve, constant air-fuel ratio under cold and hot temperature, and smoothness of operation against inclination due to inclined ground.

A float 7 is integrated with a needle value 5, and is rotated around a pin 6. A fuel supply amount is perfectly controlled by the needle valve 5 according to the motion of the float 7. An air-fuel ratio is kept constant while using an orifice ring which seals alcohol or mercury and adopts volumetric expansion caused by temperature fluctuation, and a fuel injection port needle valve. A float chamber 8 has depth to some extent. Z tubes for increasing an operatable tilting angle are prepared by four. A float chamber a fastening bolt houses an air-fuel ratio controlling needle valve, a rubber vessel sealing compressed air, and a spring for keeping the air-fuel ratio constant. A bearing is arranged in a manifold for keeping a carburetor horizontal.