A method of producing a freeze-dried bacterial cell powder wherein a suspension of bacterial cells suspended in a saccharides solution, which includes a lactic acid bacterium and/or a bifidobacterium, is freeze-dried to obtain a freeze-dried bacterial cell powder, and wherein the saccharides are trehalose and sucrose, and the concentration of each of trehalose and sucrose in the suspension prior to freeze-drying is not less than 4.5% by weight. The freeze-dried bacterial cell powder is suitable for long-term storage and can be obtained by a simple and effective freeze-drying process.本發明可以提供適於長期保存,可藉由簡單方便且有效之冷凍乾燥所得冷凍乾燥粉末狀菌體者。使糖質溶液中懸濁乳酸菌及/或雙岐桿菌之懸濁液冷凍乾燥,以得到冷凍乾燥粉末狀菌體之冷凍乾燥粉末狀菌體之製造方法,其中該糖質為海藻糖及蔗糖,且冷凍乾燥前之上述懸濁液中之海藻糖及蔗糖之各濃度為4.5重量%以上之冷凍乾燥粉末狀菌體之製造方法者,該海藻糖與蔗糖之重量比係較佳為5:1~1:5者。
