PURPOSE: To prevent an article to be stored from entering a closed space side together with air in a silo, and prevent an unfavorable motion of a main gate from happening by communicating a closed space being surrounded with top and bottom gates and a discharging passage with an intermediate location of an air feeding passage by a communicating pipe.

CONSTITUTION: A storage device 1 breaks a bridge, and smoothly discharges an article to be stored, which is stored in a silo. For this reason, a main gate 25 of a lower opening/closing means 20 and airtight gate 28 are closed, and under this state, the pressure in the silo is reduced, and then, pressurized air is fed in the silo. In this case, the pressurized air is fed to a closed space 34 also, through a communicating pipe when the pressurized air is fed to the silo. Then, respective internal pressures of the closed space 34 and silo are simultaneously increased, and the generation of a pressure difference between both parts is eliminated. By this method, the entering of air to the closed space 34 side from the silo 3 through a gap 33 between the main gate 25 and upper casing 21, or the entering of the article 2 to be stored together with the air are prevented from happening.