PROBLEM TO BE SOLVED: To obtain gas supplying conditions to a chamber and then perform processing according to the conditions even when power supply to the device to which the gas is supplied is re-started after being shut off.SOLUTION: A device to which gas is supplied comprises a preserving means 12 capable of: selectively obtaining three states A-C that represent gas supplying conditions to a chamber 10a； and, when power supply to the device to which gas is supplied is shut off, preserving the state at the time the power supply is shut off. When power supply to the device to which gas is supplied is re-started after being shut off, a determination is made as to which of states A-C the preserving means 12 is in, and then the processing to chamber 10a according to the gas supplying conditions is performed.SELECTED DRAWING: Figure 3【課題】ガス供給対象装置への電力の供給が遮断された後に再開された場合にも、チャンバーへのガスの供給状況を把握し、その状況に応じた処理を行えるようにする。【解決手段】ガス供給対象装置は、チャンバー１０ａへのガスの供給状況を示す３つの状態Ａ～Ｃを選択的に取り得ると共に、当該ガス供給対象装置への電力の供給が遮断された場合に、電力の供給が遮断された時点における状態を保持することが可能な保持手段１２を有する。ガス供給対象装置への電力の供給が遮断された後に再開された場合に、保持手段１２が状態Ａ～Ｃのいずれにあるかが判断され、チャンバー１０ａへのガスの供給状況に応じた処理が行われる。【選択図】図３
