A combustor enabled to prevent a hot premixed flame from flowing back into a main swirler zone. The combustor comprises a pilot nozzle 02 arranged at the central portion of an inner cylinder 01 opened at its end into a combustion chamber 018 and including a plurality of main nozzles 03 arranged around its outer circumference. Along the outer circumference of a flame holding cone 014 for igniting a fuel F injected from the main nozzles 03, there are disposed elliptical extension pipes 016 of an elliptical section shape which are extended from the fronts of the main nozzles 03 to have openings at the axial position of the opening of the flame holding cone 014. As a result, the hot premixed flame 013 does not flow back to the main swirler zone 015 of the circumferential edges of the openings of the main nozzles 03, so that the mixing between the fuel F and an air flow A can be improved to reduce the NOx emission while eliminating the burning of a base plate 04 and the main nozzles 03.
