[en] In the facilities for developing plutonium waste treatment (PWTF) constructed in Tokai Establishment of Power Reactor and Nuclear Fuel Development Corp. the verifying test on the volume reduction treatment of plutonium wastes which were contaminated with the plutonium generated accompanying MOX fuel production and the research on evaluating the properties of the treated solids have been carried out. The construction of the PWTF was completed in August, 1987, and the verifying test using actual plutonium wastes was started in November, 1987. The treatment facilities adopted for the PWTF were the completion collecting the results of developing the treatment technology such as incineration, melting and so on. Most of main equipments are installed in glove boxes, the automation of processes and multiple interlocking mechanism were adopted for improving the safety, and the test was advanced stepwise. The verifying test of the PWTF and its results and the development of the related technologies are reported in this paper. The soundness of PVC which wrapped plutonium wastes at the time of storage was confirmed. The volume reduction and stabilization of plutonium wastes were confirmed. (K.I.)