Aim. The investigation of response of S. cerevisiae cells to the effect of ozone in different doses and determination of total antioxidant capacity (TAC) of these cells. Methods. TAC was estimated with the chemiluminescent method when introducing ozone into S. cerevisiae cells. The damage of cells was determined by the methods of fluorescent microscopy and flow cytometry using fluorescent dye Square-460. Results. It was shown that under the ozone dosed administration into the S. cerevisiae cells suspension the chemiluminescence flash occurred in response to each new ozone doze. The flash amplitude slightly changes under low doses and decreases after achieving some total ozone dose, being characteristic for these cells. At the same time the damaged cells appear, the number of which augments with increasing the administered ozone dose. Conclusions. We assessed the TAC of S. cerevisiae cells, as the ozone dose, which may be neutralized by the systems of their antioxidant protection: 240 ± 20 nmol/106 cells. The S. cerevisiae cells are resistant to the effect of excessive ozone until its doses exceed the TAC value for these cells.