Abstract: The invention relates to a device for closing a pipe at its end side, particularly for closing the pipe so as to make it highly gas-tight, in order to obtain a simple closure of the pipe without the interior of the pipe not being contaminated when the pipe is removed. The device comprises a socket element one side of which is adapted to be attached to the pipe being closed, a closing element adapted to be placed on top of the other end of the socket element, and a clip for pressing/locking the closing element. The device according to the invention achieves a highly gas-tight metallic seal.