A method for protecting an inner wall (12) of a shaft furnace, the method comprising the steps of: providing at least one injection device (28) through the inner wall (12) of the shaft furnace, the injection device (28) being configured to inject protective material into the shaft furnace; and injecting on demand the protective material into the shaft furnace through the injection device (28), in such a manner that the protective material builds up to form a protection wall between the interior of the shaft furnace and the furnace wall (12).