Device for injecting gas into a hot melt, particularly molten metal, which device is suitable for being installed in the wall, particularly the botom wall, of the container holding the melt. The device comprises three main sections: 1) a front section (5) of refractory material which is resistant to the melt in question, and which has a number of perforations (10) for introduction of gas into the melt, 2) a middle section (3, 4) which at least partly consists of heat conductive material and possesses a number of perforations (11) communicating with the perforations (10) of the front section (5), 3) a rear section (1, 2) wherein at least the outer (peripheral) part is of heat conducting material, which rear section in or close to its peripheral parts has a helical duct (13) communicating with the perforations (11) of the middle section (3, 4) and adapted to pass said gas from an external gas source. The middle section is preferably divided into two part sections (3 and 4) of which at least one, preferably the foremost part section (4), is made of a material of high heat conductivity, preferably copper or a copper alloy, whereas the rear part section (3) preferably consists of steel.