The invention concerns a gas sink in the form of an interstitial flushing device in which the gas passage ducts are in the form of interstices. The opposite walls of the interstices are monolithically interconnected by flat bridges of refractory material. The gas sink can be produced by means of a conical hollow body (1) whose side wall (2) comprises apertures (3). The hollow body (1) is inserted into a casting mould (4) which is subsequently filled with a refractory casting compound.
