A fuel injection device is provided. The device includes a pilot injector opening out into a venturi and an annular row of multipoint injection orifices opening out axially in a downstream direction and radially outside the venturi, the venturi being connected at its downstream end to a separation wall. The outer peripheral edge of the separation wall has a diameter greater than the diameter of the annular row of injection orifices, whereby the separation wall forms a thermal protection screen for these orifices against heat radiation coming from the chamber.