[en] Purpose: To enable substantially permanent wastes storage by calcinating radioactive wastes, storing them in the recesses of metal plates and laminating and pressurizing the metal plates in a container to solidify them. Method: Radioactive wastes are calcinated and stored in the recesses formed in metal plates. The metal plates are made of a metal, i.g., lead metal, having a good fittability to the calcinated products and the recesses are formed corresponding to the configuration of the calcinated products. Then, the metal plates are moved laterally and vertically so that the metal plates containing the calcinated products in their recesses may be laminated in the most compacted structure, and the entire contents are compressed to solidify. Accordingly, the calcinated products are disposed in the metal matrix, can be stored with safe for a long time and the volume reduction ratio can be decreased significantly. (Yoshino, Y.)