A device for releasable fixed holding of a welding wire in a welding wire guide is described. This device is characterized in that the welding wire guide includes a cage for radially displaceable braking bodies, wherein a locking cone surrounds the braking bodies, and that, of the two cooperating functional elements, formed on the one hand by the welding wire guide and on the other hand by the locking cone, one is mounted in a non-displaceable manner in a holder and the other is mounted to be axially displaceable against a spring force with respect to the non-displaceable functional element.