PROBLEM TO BE SOLVED: To efficiently obtain a dried bacterium cell useful as a starter in production of a fermented food, etc., by freezing a culture product of a bacterium cell by dripping water drops of the culture product of the bacterium cell on a metal plate cooled to a temperature equal to or lower than the freezing temperature to quickly freeze the culture product. SOLUTION: In this method for producing a dried bacterium cell by drying a cultured product of a bacterium cell in vacuum, a precultured bacterium [e.g. Bifidobacterium longum SBT 2928 (FERM P-10,657)] is inoculated into a medium and cultured at 37 deg.C for 16 hours to prepare a culture product of the bacterium cell. The freezing of the culture product of the bacterium cell is carried out by dripping droplets of the culture product of the bacterium on a metal plate cooled to a temperature equal to or lower than the freezing pressure. The droplets are quickly frozen into frozen particles, which are freeze- dried at a room temperature to efficiently give the objective dried bacterium cell useful as a starter in producing a fermented food.