A gas-cooled welding gun for an arc welding device, comprising an electrically conductive current contact tube disposed concentrically within an electrically conductive outer tube and separated therefrom by an intermediate space. The current contact tube includes a wire guiding channel for a welding wire. A plurality of spacers is disposed at intervals in the intermediate space between the current contact tube and outer tube, electrically insulating these components from each other. A shielding gas is provided in the intermediate space to cool the system and openings in the spacers allow the gas to flow therethrough. Structures are provided on the current contact tube which increase the overall surface area thereof. Regions of the surface of the current contact tube not covered by spacers are exposed toward the intermediate space and therefore to the shielding gas.