To increase the feeding speed of an irradiation target and prevent the occurrence of a non-irradiation area of electron beams on the surface of the irradiation target.

The device is equipped with a feeding device 4 for feeding a spherical or oblate-spherical irradiation target 2 in a feeding direction X, two electron beam accelerators 8a, 8b for irradiating electron beams 10a, 10b to the irradiation target 2 on the feeding device 4 in oblique directions from the upper right and left sides with respect to the Y direction crossing the feeding direction X so that the irradiation areas of the electron beams 10a, 10b are rectangular and the long sides of the respective irradiation areas are disposed along the feeding direction X, and a rotating device 6 for rotating the irradiation target 2 in each irradiation area of the electron beam accelerators 8a, 8b in a frontward or backward direction A with respect to the feeding direction X on the feeding device 4.