Abstract: An electron beam sterilizer has a bottle holder 28 provided with a rotation shaft 38, a neck gripper 70 mounted to a lower end of the rotation shaft 38, a rotating body 30 for rotating and moving the neck gripper 70 and a rotator revolver (segment gear 54, pinion gear 46, disc-shaped cam 66, etc.), and while conveying the resin bottle 2 in the state of being held, the resin bottle 2 is sterilized by irradiation with the electron beam through the irradiation window 19 of the electron beam irradiation device 18. The entire surface of the resin bottle 2 is completely sterilized by being rotated by the rotator during the movement in front of the irradiation window 19 and, thereafter, the rotator is inverted in position to return the neck gripper to thereby discharge the bottle.