The apparatus with the help of ultrasonic mechanical high-frequency vibrations of the diffuser membrane turns essential oils into submicron aerosol without heating and loss of healing properties. Oil microparticles well-distributed in the air effectively attack viruses and bacteria present in the air. After a single dispersion essential oils remain in the air up to one day. Diffuser “EfA” turns every drop of oil into 90% of submicron activated particles bactericidal properties of which drastically increase. The dispersion is safe, pleasant and can be performed in the presence of people. The apparatus allows broad application of essential oils both in medicine and in private life with the aim of disinfection and simultaneous aromatization of a flat or office (especially during epidemics of respiratory infections), immunity correction, elimination of odor nuisances indoors, formation of good psychological situation.