In a storage air conditioner that adjusts the composition of air in a storage (1) such as a container, the storage air in the storage (1) maintained at a low oxygen concentration is returned to the atmosphere. Reduce time. A high oxygen gas generated by first and second composition control units (40, 60) capable of generating a low oxygen concentration gas having a lower oxygen concentration than the atmosphere and a high oxygen concentration gas having a higher oxygen concentration than the atmosphere. The controller (110) has an oxygen concentration recovery control unit (111) that supplies oxygen concentration gas to the internal space of the storage (1) and returns the oxygen concentration in the internal space to the target concentration corresponding to the atmosphere. Provided. [Selection] Figure 3【課題】コンテナなどの収納庫（1）の内部の庫内空気の組成を調節する庫内空気調節装置において、低酸素濃度に維持された収納庫（1）の庫内空気を大気相当に戻す時間を短縮する。【解決手段】大気よりも酸素濃度が低い低酸素濃度ガスと大気よりも酸素濃度が高い高酸素濃度ガスとを生成可能な第１，第２組成調節部（40，60）で生成された高酸素濃度ガスを収納庫（1）の内部空間へ供給し、内部空間の酸素濃度を大気に相当する目標濃度に戻す酸素濃度回復運転を行う酸素濃度回復制御部（111）を制御器（110）に設ける。【選択図】図３
