Abstract: A cracking furnace for thermal cracking of hydrocarbon feedstocks has a central burner provided vertically at the center of the ceiling of a combustion chamber, side burners provided vertically at both sides of the central burner, and reaction tubes vertically arranged between the central burner and resepctive side burners. The reaction tubes are arranged in rows along the longitudinal direction of the chamber and form arch bands at the lower part of the combustion chamber. A combustion gas-inducting duct is provided at the bottom of the chamber, a quenching heat exchanger is provided at the upper part of the chamber, and a reaction tube exit header is provided for connecting a plurality of exits of the reaction tubes to the quenching heat exchanger.