Abstract: In a method of deoxidizing and/or carburizing a metal, particularly steel, bath using an immersed nozzle consisting of two concentric tubes, the central tube of the nozzle is fed with an oxidizing gas during the or each oxidation phase, then with a scavenging gas, then with a neutral gas carrying carbon powder or powder containing carbon during the or each deoxidation or carburization phase and finally with a scavenging gas, the outer tube of the nozzle being fed with a protective fluid or different protective fluids during both the oxidation and deoxidation or carburization phases.