PURPOSE: To ensure the isolation from surroundings, improve the radiation shielding effect, and simplify the structure of a storehouse by constitution it of steps of loading of a columnar body the horizontal and vertical positioning, and the housing of the columnar body in a housing tube.

CONSTITUTION: A columnar body P, which is kept housed in a transportation cask C, is carried from the ground through a loader 4 into a cell 1 by a crane 3b. Then, the body P is taken out from the cask C and is horizontally positioned by a carrying means 21 in the cell. After having positioned the body P, it is raised by a lift 25 and is inserted into a desired housing tube 16, and the weight of the body P is supported and the position where it is housed is set by using a fixing means. A tray supplying means 30 supplies trays 28 to the lift 25 of the carrying means 21, and empty casks C are returned to the ground. When the post P generates the decay heat of a radioactive substance, moreover, the exchange with the low-temperature air due to the thermal ascending current controls the rise in the temperature of the body P and the tube 16. Further, the freedom is given to the thickness and materials of an upper shielding wall 11 of the cell 1 by loading and unloading the columnar body P from below the tube 16.