Ozone (O 3) has many industrial applications such as in sterilization. One of the long-term O 3 preservation methods is molecular storage in clathrate hydrate. In this study, an experimental system was developed for continuously forming O 3 + O 2 + CO 2 hydrates. The parameters that affect the continuous operation of the system and that lead to increases in the concentration of O 3 in the hydrates were also experimentally evaluated, implementing the method of quality engineering. After optimizing these operating parameters, the O 3 storage capacity in the hydrates was measured to be 0.26 wt % at 2 h of total operation time. By X-ray diffraction, it was found that the produced sample contained hydrates, and longterm preservation for 6 months was possible at the temperature of general freezing warehouses.