Abstract: A radioactive decontamination method for decontaminating a radioactive-contaminated object by using methylene chloride in place of conventionally used hydrocarbon fluoride or perchloroethylene. The radioactive-contaminated object is impacted by methylene chloride solution. Before the impacting, a preparatory step is executed as required in which radioactive contaminant, which is usually radioactive-contaminated epoxy-resin paint layer on a part used in a nuclear facility, is impregnated with methylene chloride solution so as to swell, thus facilitating exfoliation of the contaminant from the object. The methylene chloride solution is filtered and distilled so as to be decontaminated and subjected to a repeated use for impacting the radioactive-contaminated object.