The endoscope reprocessor includes a concave processing tank 11 in which the endoscope is disposed, a lid 21 for covering the processing tank 11, an atmosphere opening pipe line 31 connected to the processing tank 11 to open the processing tank 11 to the atmosphere, A gas filter connecting portion 35 arranged in the atmosphere opening pipe line 31, an opening / closing valve 34 arranged on the processing tank side of the gas filter connecting portion 35 in the atmosphere opening pipe passage 31, and an internal pressure of the processing tank 11 The pressure sensor 41 is disposed on the side closer to the processing tank than the opening / closing valve 34 in the atmospheric release pipe line 31, or is connected to the treatment tank 11, and even when the on-off valve 34 is in a closed state, pressurization for pressurizing the treatment tank 11 Section 51, and a control section 61 for controlling the on-off valve 34 and the pressurizing section 51.内視鏡リプロセッサは、内視鏡を配置する凹状の処理槽11と、処理槽11を覆う蓋21と、処理槽11に接続されて処理槽11を大気開放する大気開放管路31と、大気開放管路31に配置されたガスフィルタ接続部35と、大気開放管路31において、ガスフィルタ接続部35よりも処理槽側に配置された開閉弁34と、処理槽11の内圧を検知する圧力センサ41と、大気開放管路31において開閉弁34よりも処理槽側に配置され、又は、処理槽11に接続され、開閉弁34が閉状態にあっても処理槽11を加圧する加圧部51と、開閉弁34および加圧部51を制御する制御部61と、を含む。
