A combustion chamber includes a bottom wall having at least one opening, at least one sleeve mounted upstream of the bottom wall and fixed to the bottom wall, a closing ring defining an annular groove with the sleeve and fixed to the sleeve, and at least one air and fuel injection system having an axis, mounted in the opening of the bottom wall. The injection system has an annular flange extending radially with respect to the axis and is mounted in the groove with radial clearance. A baffle is situated downstream of the bottom wall and is fixed to the sleeve and/or to the bottom wall.