In recent years, the volume of sake and the number of its breweries have been declining. Covid-19, spreads from 2020, now decrease these less and less. To sustain the sake brewing industry under its market shrinkage, it is essential for each breweries to operate with cost awareness. In this research, we analyzed the cost structure of the sake brewing industry by estimating the translog cost function of sake using Japanese prefecture-wise panel data. We found significant differences in the cost structure among types of sake, but no significant differences among prefectures and time periods.