Relevance. The positive aspects of disinfecting ozonation of hatching eggs allow us to expect successful application of the method not only in large but also in small-scale farms, as well as for experimental and industrial purposes in laboratories and bio-enterprises related to the technological process based on the incubation of a small number of eggs. This determines the importance of expanding the range of ozonizers due to numerous portable devices. There are no clear recommendations for these devices and this causes the need to search for the most effective and harmless modes for the embryo, and schemes of disinfecting ozonation.Methods. The study used fertilized chicken eggs “Hysex Brown” and a portable ozonizer “OZON-OviV”. Ozone concentration 2.0 mg / l. Eggs were treated in a specially made chamber. Technology-1: twice for 30 minutes before incubation and on the 3rd day of incubation. Technology-2: three times for 30 minutes before incubation, on days 3 and 5. The range of studies included: assessment of total microbial contamination (densitometry); identification of microorganisms (MALDI-TOF-spectrometry); biological control of incubation (fertility, hatchability, mortality, developmental abnormalities); assessment of the adequacy of the internal organs (MicroCT); embryo morphometry (weight, length, chest circumference) and calculation of development proportionality indices; histological assessment of the liver.Results. The total ozone concentration during treatment by two methods was 240 mg/l and 360 mg/l, respectively. The disinfecting efficiency of ozonation has been proven, providing a decrease in the level of total microbial contamination by 30% and 40% with double and triple treatment. A tendency to maintain a low total microbial contamination, compared to intact eggs, up to 14 days of incubation has been revealed. The dynamics of the microbial landscape indicate the bacteriostatic effect of ozone in the concentrations used on a wide range of microorganisms. Microtomographic and histological methods confirmed the harmlessness of the technologies used. Along with the more pronounced antibacterial effect of technology-2, the presence of a stimulating effect on the body of the developing embryo was revealed, which determines the preference for its choice.