This paper describes a generation method of ozone using a silent discharge ozonizer, which is cooled down to cryogenic temperature by liquid nitrogen. The ozonizer was consisted of two metal electrodes and one dielectric barrier covering the lower electrode surface. In order to cool down the discharge space between the dielectric barrier and the upper electrode, the ozonizer was placed in an inner vessel of a metal cryostat whose outer vessel was filled with liquid nitrogen. It was found that the ozone concentration and ozone yield were increased with decreasing temperature. Especially, the cooling effects were remarkable in high specific energy region. The maximum ozone concentration of 146 g/m³ and ozone yield of 212.5 g/kWh were achieved at 170 K. Temperature distribution within the ozonizer was theoretically analyzed inorder to clarify the effects of the dielectric barrier material and the electrode gap space.