A method for producing a foamed slag (1) on a metal bath (2) in a metallurgical furnace (3), in which a mixture (4) containing at least one metal oxide and carbon is introduced into the furnace (3), the metal oxide is reduced by the carbon below the slag (1) that is located there, and the gases produced during the reduction process form bubbles such that the slag is foamed. In order to optimize the formation of foamed slag, the mixture (4) is delivered into the furnace (3) in such a way that a desired height (h) or a desired section of the height (h) of the layer of foamed slag (1) is generated or maintained.