The object of this invention is a disinfecting method to be utilised for cleaning. It is characteristic of the invention that hydrogen peroxide (H2O2) is sprayed from one or more containers (9) by fluid pressure caused by one or more pumps ( 10) through one or more spraying elements (4) into one or more vaporising elements (5) where the hydrogen peroxide (H2O2) forms hydrogen peroxide gas by means of which cleaning/disinfecting is performed, and that warm gas (6) is blown by one or more blowers (1) through vaporising element(s) or vaporising sur- face(s) (5) into the cleanable target(s) or space. A disinfecting device to be utilised for cleaning is also presented. It is charac- teristic of the invention that the disinfecting device comprises one or more containers (9) and one or more pumps (10) for containing and transferring hydrogen peroxide (H2O2) through one or more spraying elements (4) into one or more vaporising elements (5).
