A method and a device for disinfecting inner surfaces of freezers and the like includes the production of a microfilm of sanitizing solution on the inner surfaces and on the devices contained in the freezers and the like, by a method which comprises two sequential steps, a first step in which 100% of the inner surface of the internal environment of the freezer or the like is completely saturated with a mist of sanitizing solution, which is then condensed, and a second step in which the air containing this mist is passed through a filter provided with means that absorb the sanitizing solution, both steps being implemented by closed-loop recirculation means (looping).