PURPOSE: To make it possible to wash and to disinfect an endoscope in a short time using hydrogen peroxide by providing a process-selecting means selecting a disinfection process with hydrogen peroxide gas and a disinfection process with a liq. of hydrogen peroxide.

CONSTITUTION: A washing and disinfection apparatus 1 provides a usual washing and disinfection process performed at the end of a day and a washing and disinfection process performed in a short time between different cases of diseases in such as a group examination and they are selected by means of a control unit to perform a different kind of action. In case of the washing and disinfection process performed in a short time between different cases of diseases in such as a group examination, after the washing process, a water-feeding valve 34 is opened again to feed a city water to a bath 5 of a washing tank 3 and a pipe path switching valve 29 is made open to a hydrogen peroxide fluid-feeding pipe path 31 side to feed directly the hydrogen peroxide fluid in the tank 5 of the washing bath 3. The hydrogen peroxide fluid is diluted with the fed water to a concn. of 3-10% and the diluted fluid is stored and is sprayed from a spray nozzle 8 on the outer surface of an endoscope 2 to perform an disinfection of the inner and the outer surfaces with the hydrogen peroxide fluid of a low concn.