To provide an assembling/disassembling possible storage device to stackably perform storage since there is a case where a wall cannot be holed or damaged to keep protective caps.

The protective caps are kept by being vertically stacked. The device has a cylindrical shape and is constituted of vertical posts (5) raised from a bottom board (4) and horizontal deviation preventing materials (7) having an opening (3) in the front surface of the device, so as to smoothly take out even a protective cap on the lowest stage even when some protective caps are superimposed on each other. The device is made to be assembled/disassembled in order to be easily carried.