An endoscope reprocessor includes a first connector receptacle configured to connect a first connector connected to a cylinder in an endoscope, a first switching device configured to switch the first connector to one of a sealed state and an unsealed state, a first gas feeding device connected to an air introduction port to introduce gas, and a processor configured to perform control such that first driving for driving the first gas feeding device by bringing the first connector into the unsealed state is performed and second driving for driving the first gas feeding device by bringing the first connector into the sealed state is then performed.