A treatment device for sterilizing containers by an electron beam includes a carousel that comprises a rotary holding plate supporting a plurality of treatment stations, each station including a sterilization device comprising an electron beam emitter, and a holding device for holding a container under the emitter. The treatment device includes a protection system for stopping the rays emitted by the emitters, the protection system comprises an annular segment-shaped, open stationary channel that is mounted in a stationary manner under the holding plate and forms, with the latter, a protective chamber in which the holding device supporting the containers moves, the channel having an open upstream end, for the inlet of the containers to be treated into the protective chamber, and an open downstream end, for the outlet of the treated containers from the chamber.