Abstract: A device for receiving, filling, and seal-welding a high-pressure vessel that can be received and clamped between an upper lid and a lower lid. A filling chamber is provided in the upper lid. The chamber is open on one side to a filling hole in the facing wall of the high-pressure vessel and sealed tightly at the other end by a disk made of transparent crystalline material. An interruptible filling line terminates in the chamber, and with a welding energy radiation source being located above the disk, whose radiation penetrates the crystalline material, is simpler in construction and universally applicable as well as operationally more economical. The upper lid, on its side facing the high-pressure vessel, has an annular seal which can be brought into tight contact with the facing wall of the high-pressure vessel.