To provide a radioactive waste container capable of utilizing thermal energy emitted from radioactive waste emitting heat, such as glass-solidified matter by efficiently converting the thermal energy into electrical energy.

The radioactive waste container 10 comprises a container body 11 for accommodating the radioactive waste emitting heat, a coated heat-insulation section 12 formed and coated on the exterior side of the container body to block dispersion through the exterior surface of the container body of the heat emitted from the radioactive waste and a thermoelectric element 13, penetrating the heat insulation section from the front face to the rear face and generating electricity due to the difference in the temperature at between one end positioned at the container body side and the other end exposed to the outside. The heat, emitted from the radioactive waste, is confined to be within the interior by the heat insulation effect of the coated heat insulation section to increase the temperature difference between the exterior surface of the container body and the exterior surface of the coated heat-insulating section.