To mix and subdivide a food in a disposable vessel.

The subdividing method of a mixed food of subdividing a mixed food such as milk shake or the like comprises a step of un-stacking a disposable vessel 3 for only one use at a filling position; a step of filling the vessel 3 at least partly with the food at the filling position; a step of sealing the vessel 3 filled with the food; and a step of moving the sealed vessel 3 to a subdividing position where the food is mixed in the vessel 3 wherein the food is mixed at the subdividing position in the vessel 3 by using an impeller 1 mounted on a cover 2 of the vessel.