Electron beams are irradiated to substantially identical sterilization surfaces on a container from a first upstream electron-beam irradiating device and a first downstream electron-beam irradiating device that are spaced with a predetermined distance upstream and downstream on a container carrier path. A sterilization controller controls the sum of electron beam outputs irradiated from the upstream electron-beam irradiating device and the downstream electron-beam irradiating device so as to allow sterilization on the sterilization surfaces of the container.
