In a turbomachine comprising in an annular shell of metal material (12, 14) and in a flow direction F of the gas, an injection assembly of a fuel (20; 22), a combustion chamber annular composite material (24) and an annular nozzle of metal material (42) forming the fixed blade inlet stage of a high pressure turbine, it is expected that the combustion chamber is held in position in the casing annular metal by a plurality of flexible metal tongues (58, 60) each having three legs connected in star, the ends (62a, 62b; 64a, 64b) of two of the three legs being integrally fixed to a downstream end (68, 70 ) of the combustion chamber by respectively first (72a, 74a) and second (72b, 74b) fastening means and the end (76, 78) of the last of these three branches being securely fixed to the annular casing ( 12, 14) by a third fastening means (80, 82).