An injector (1) of a propellant combustion member, comprising - a first supply (31) - a second supply (41), the first supply (31) being linked to a plurality of supply channels (33) disposed around a longitudinal axis (Z-Z), the second supply (41) being configured in such a way as to supply an injection chamber (5), said injection chamber (5) being linked to a plurality of supply sleeves (44) by means of injection ports (45), each supply channel (33) being surrounded by a coaxial supply sleeve (44), characterised in that the injector (1) further comprises a discharge chamber (62) linked to a discharge conduit (61) for discharging the second propellant, said discharge chamber (62) being arranged to discharge second liquid propellant from the injection chamber (5), the injector (1) being configured in such a way as to inject the second propellant in a uniform manner via the injection ports (45).