<p>Consideration is given to the problem of creation of fine aerosols by a novel method consisting in the droplets of a liquid breaking up in a series of antinodes of a powerful ultrasonic field. This makes it possible to obtain an aerosol cloud with a droplet size under 50 μm with a high efficiency at relatively low energy expenditures. A mathematical model of multistage spraying of droplets in an acoustic field has been proposed, which is based on the energy approach with hydrodynamic criteria, with the Weber number and the acoustic Bond number being basic ones. Critical conditions have been determined for the breakup of droplets, and also their limiting dimension. Possible mechanisms of disintegration of droplets, as they pass successively through the antinodes of the ultrasonic field, have been described depending on the initial size of the droplets and the velocity of their motion, the surface tension of the liquid in the droplets, and acoustic pressure. From the results of measurements of the dispersion parameters of the aerosol obtained in the process of multistage spraying of the liquid in the acoustic field, free parameters of the mathematical model of the process have been determined.</p>