According to the present invention, there is provided a stirred tank for storing yeast slurry to be supplied to fermentation tanks where fermented foods such as beer are fermented, is characterized in that a stirring impeller is provided within the stirred tank and so constructed that a maximum diameter of a rotation body defined by the rotation of the stirring impeller is 60-90% of the inner diameter of the stirred tank, and the height of the rotation body is 70% or more of a standard depth of the yeast slurry normally stored in the stirred tank.