A storage system comprises: a heat-insulating outer shell (1) capable of insulating inner space (V); an ice storage water tank (4) capable of storing water therein disposed in an ice storage water tank disposing space (5) provided in the inner space (V) of the heat-insulating outer shell (1); a storage space (3) for storing objects (2) to be stored provided in the inner space (V) of the heat-insulating outer shell (1); an outside-air inlet opening (1a) provided at a lower portion of the heat-insulating outer shell (1), the inlet opening being capable of introducing outside air into the inner space (V); an inside-air outlet opening (1b) provided at an upper portion of the heat-insulating outer shell (1), the outlet opening being capable of discharging inside air from the inner space (V) of the heat-insulating outer shell (1) to the outside; and an object entrance-exit opening (7) provided at an upper portion of the heat-insulating outer shell (1) for allowing entrance-exit of the objects (2) to and from the storage space (3).