An endoscope cleaning/disinfecting apparatus includes: a cleaning/disinfecting tank, a lid portion, an accommodation detecting section 103, an opening/closing detecting section 104, a cleaning/disinfecting section 106, a cleaning/disinfection detecting section 105, an informing section 107, a judging section 102 judging a case where the opening/closing detecting section 104 detects a closed state of the lid portion before the cleaning/disinfection detecting section 105 detecting driving of the cleaning/disinfecting section 106 after the accommodation detecting section 103 detecting that an endoscope is accommodated in the cleaning/disinfecting tank as a first closed state； and a control section 101 performing control of driving the informing section 107 to issue a warning when the opening/closing detecting section 104 detects an opened state of the lid portion before the cleaning/disinfection detecting section 105 detecting driving of the cleaning/disinfecting section 106 after the judging section 102 detecting the first closed state.
