To provide a compact electron beam irradiation device capable of performing sterilization by electron beams suited to the kind of an object to be sterilized.

By controlling the amount of electrons emitted from an electron gun 3 and made incident on an acceleration tube 6 corresponding to the kind of the object 1 to be sterilized by a current amount control means 18, the electron beams suited to the object 1 to be sterilized is irradiated, and since the need of using a tank like an electrostatic type electron beam irradiation device is eliminated, this device is compacted. Also, by providing a speed control means 17 on a conveyor 2, by slowing or accelerating the carrying speed of the conveyor 2 in the case that the size and weight of the object 1 to be sterilized exceeds a range controllable by the current amount control means 18, the energy value and irradiation amount of the electron beams irradiated to the object 1 to be sterilized become the appropriate size, and thus, the sterilization is performed by more suitable electron beams and the degradation of the conveyor 2 or the like is prevented.