PROBLEM TO BE SOLVED: To provide a cleaning system, a cleaning unit and a cleaning method having improved cleaning power. SOLUTION: A tubular liquid storage container in which a pH adjusting liquid is stored inside and a hollow portion above the pH adjusting liquid, and a hollow portion connected to the top of the liquid storage container are filled with carbon dioxide gas at a constant adjustment pressure. The filling path, the carbon dioxide gas cylinder connected to the input side of the filling path, the liquid feeding path connected to the lower part of the liquid storage container and the pH adjusting liquid to be sent to the pipeline of the equipment to be cleaned with the adjusting pressure, and the liquid storage container. It is provided with a stock solution introduction path for introducing a cleaning stock solution for preparing a pH adjusting solution in a liquid storage container connected to the above, and a stock solution tank provided on the input side of the stock solution introduction path for storing the cleaning stock solution. The adjusting pressure is obtained by adjusting the filling pressure of the carbon dioxide gas cylinder with the filling pressure regulator provided in the filling path and the liquid feeding pressure regulator provided in the liquid feeding path, and the pH adjusting liquid is used to adjust the pipe line of the equipment to be cleaned. To wash.【課題】洗浄力が向上した洗浄システム、洗浄ユニット及び洗浄方法を提供する。【解決手段】ｐＨ調整液を内部に溜めｐＨ調整液の上方を中空部とするチューブ状の液溜め容器と、液溜め容器の頂部に接続され中空部に炭酸ガスを一定の調整圧力で充填する充填経路と、充填経路の入力側に接続された炭酸ガスボンベと、液溜め容器の下部に接続されｐＨ調整液を調整圧力で被洗浄器具の管路に送液する送液経路と、液溜め容器に接続され液溜め容器にｐＨ調整液を作製するための洗浄用原液を導入する原液導入経路と、原液導入経路の入力側に設けられ洗浄用原液を溜める原液タンクを備える。調整圧力は炭酸ガスボンベの充填圧力を充填経路に設けられた充填圧力調整器、及び送液経路に設けられた送液圧力調整器によって調整して得られ、ｐＨ調整液によって被洗浄器具の管路を洗浄する。
