Abstract: The device described serves to supply processing gas to an ionic implanter isolated from its environment by an electrically conductive enclosure connected to earth. Said gases are supplied by intermediate containers arranged permanently inside the enclosure and periodically filled from gas sources arranged outside, via pipelines which are at least partly insulated and pass through the enclosure. Each phase of filling the containers which is effected during the periods when the implanter is stopped, is followed by a gas evacuation phase through said pipelines. The invention overcomes the problems relating to the replacement of gas cylinders arranged around the enclosure in conventional installations.