TECHNOLOGY FOCUS - BIOLOGY - Preferred Method: The method involves controlling the ratio of fine particles (P1) and (P2). The method involves controlling particle size of fine particles and at least one properties including spray velocity of the fine particles. The particle size of the fine particle (P1) is controlled to a size larger than the fine particle (P2). The method involves supplying the fine particles (P1) and (P2) at a discharge wind speed by spraying process. The discharging process involves assigning atomization for each fine particle in to-be-processed space, and discharging the particle (P1) at discharge speed which is less than the discharge speed of the particle (P2). The method involves spraying the particles using gas containing less amount of carbon dioxide than carbon dioxide in the atmosphere. The method involves adjusting supply ratio of the first and second atomization particles supplied by the first and second portions. Preferred Device: The device comprises raw material container for hypochlorous acid aqueous solution, and apparatus for preparing acid aqueous solution which simultaneously produces the solutions (S1) and (S2) from the hypochlorous acid containing raw material in raw material container. The first atomization portion comprises first bath containing the solution (S1), and first atomization mechanism for atomizing the solution (S1) in the first bath. The second atomization portion comprises second bath containing the solution (S2), and second atomization mechanism for atomizing the solution (S2) in the second bath. The device comprises at least one particle size control unit in each atomization portions. The atomization portions comprise an ultrasonic atomization apparatus. The device comprises at least one discharge wind speed control unit in each of the atomization portions. The atomization portions of the device comprise a deflection mechanism for adjusting the spraying direction of each of the atomization particles. EXAMPLE - No suitable example given.