Abstract: A welding device (10a; 10b) for welding an outlet element (12a; 12b), in particular a valve, to a packaging material (14a; 14b), has at least one, in particular self-supporting, anvil (16a; 16b) comprising at least one receiving region (18a; 18b) for receiving the outlet element (12a; 12b) that is to be welded, and has at least one welding die (20a; 20b), in particular a sonotrode, which is configured to interact with the anvil (16a; 16b) for a welding of the outlet element (12a; 12b) to the packaging material (14a; 14b), wherein the welding device (10a; 10b) comprises at least one magnet unit (22a; 22b), which is configured to at least temporarily hold the anvil (16a; 16b) in a welding position, in which the welding die (20a; 20b) is configured for welding the outlet element (12a; 12b) to the packaging material (14a; 14b)