An afterburner chamber includes a burner ring having housed therein an annular fuel strip that is pierced by orifices and that is mounted inside an annular thermal protection tube, and an ignition spark plug penetrating into the inside of the burner ring. The protection tube and the burner ring have orifices for passing air. The chamber also includes a device for ventilating the orifices of the fuel strip that are situated in the immediate vicinity of the spark plug.