Nowadays, electron beam (EB) irradiation method is attracting attentions as useful medical tools sterilization, which has the advantages such as safety, zero emission and high speed processing. In this trend, in addition to present main object (the low-density medical tools: ex. Operation dress), other various objects are strongly desired that will be applied of EB sterilization method. Mitsubishi Heavy Industries, Ltd. (MHI) has succeeded in realization of high efficiency continuous EB sterilization processing for high-density medical tools, vessel surface, and so on. Further, compact EB systems are also developed, which can also be applicable for above mentioned objects.