To provide a method and device for electron beam irradiation of high process efficiency and productivity where a both-side irradiation is efficiently performed with a single electron beam accelerator.

There are provided an electron beam irradiation device which circulates in a shield space for shielding X-ray generated secondary by electron beam irradiation while performing one-side irradiation with the object sidewise, and an object translation means which, provided between a lower stream side and an upper stream side in transportation direction of irradiation point, returns the object from the lower stream side to the upper stream side while translating it. An object, after irradiated by one surface, returns onto the upper stream side of irradiation point by the translation means, and an opposite surface which is not irradiated is allowed to face the electron beam irradiation side. Thus, both surfaces of the object is irradiated during two rounds.