The method involves using a cleaning agent containing tenside diluted in aqueous solution with 10.5-pH value for removing aborticide or inactive microorganisms from surgical and medical instruments. The microorganisms include bacteria, viruses, yeasts and fungi. The cleaning agent also contains alkali hydroxide, alkanolamine, phosphate or polyphosphate, and corrosion inhibitors. Cleaning is performed in an ambient temperature of 60 to 93 degrees Celsius. An independent claim is included for the use of the cleaning agent in cleaning and disinfecting medical and surgical instruments after use.
