Patent ID: 7435980

Claim:
An electron beam irradiation device for irradiating an electron beam to a belt-shaped irradiated object while making the irradiated object travel, an electron beam generating section which generates the electron beam and emits the electron beam to an outside from a transmission window part; an irradiation chamber adjacent to the transmission window part of the electron beam generating section, having partitions surrounding a periphery, a feed-in opening which opens on the partition to allow the belt-shaped irradiated object to be fed in, and a feed-out opening which opens on the partition to allow the belt-shaped irradiated object to be fed out, and formed as a closed space filled with inert gas, in which the electron beam emitted from the transmission window section is irradiated to the belt-shaped irradiated object fed in from an outside and travels the inside; and an oxygen cutoff section adjacent to the irradiation chamber on an upstream side in an irradiated object traveling direction, having a feed-in opening for feeding in the belt-shaped irradiated object, and a feed-out opening for feeding out the belt-shaped irradiated object, and formed as a closed space, in which the belt-shaped irradiated object travels to be introduced to the irradiation chamber, the inert gas is blown to the irradiating surface side of the irradiated object, and oxygen in the air accompanying a vicinity of a surface of the irradiated object to flow in is shut off or diluted, wherein: the oxygen cutoff section surrounds the irradiated object with a surface side partition facing a side of the irradiating surface of the traveling belt-shaped irradiated object, a backface side partition facing to a side opposite to the irradiating surface of the irradiated object, and a pair of sideface side partitions facing both sideface sides of the irradiated object, a gap Ws between the surface side partition and the backface side partition of the oxygen cutoff section, and a gap We between the surface side partition and the backface side partition of the irradiation chamber and across the belt-shaped irradiated object in the irradiation chamber satisfy an inequality Ws<We, the gap Ws between the surface side partition and the backface side partition of the oxygen cutoff section is made uniform or almost uniform throughout an entire area of the oxygen cutoff section and, a blowing slit for the inert gas is provided on the surface side partition of the oxygen cutoff section, with a blowing opening thereof being not projected form or caved in the surface side partition of the oxygen cutoff section.