19 is disposed between the abutting edge and the combustion chamber wall 5 the seal is preferably flexible in order to be able to compensate for thermal expansion it can be produced as metal for example the stud 23 which retains the burner insert wall 9 in the retaining groove 21 of the grooved ring 7 has holes 25 which allow the cooling air to flow to the burner 1 the cooling air is deflected off the burner wall 7 in the direction of the interior of the combustion chamber and flows through the annular gap 29 between the burner wall 27 and the burner insert wall 9 into the interior 2 of the combustion chamber the intermediate space between the burner 1 and the burner insert 3 is sealed off from the combustion chamber plenum 4 by a piston ring 31 serving as a seal in the inventive combustion chamber the cooling air drawn in to cool the burner insert wall 9 flows into the combustion chamber through an annular gap 29 directly adjacent to the burner outlet 33 and is supplied to the combustion process this improves the thermo acoustic response of the combustion chamber thereby allowing the quantity of pilot gas supplied to be decreased and therefore no x emissions to be reduced fig2.