The present invention addresses the problem of providing a fermented milk food having high survivability of lactic acid bacteria during preservation, suppression of acidity increase, little decrease in viable cell number, and less flavor deterioration. This fermented milk food production method having solved the problem is characterized by inoculating and culturing a lactic acid bacterium in a culture medium, the culture medium having milk as the principal component, and having added thereto: glucose by an amount at which substantially all of the glucose is assimilated by the end of culturing； and fructose by an amount two times or more of the glucose in mass ratio.本發明係以提供一種保存中之乳酸菌的生存性較高，且可抑制酸度的上升，生菌數之減少與風味劣化較少的發酵乳食品為課題。解決該課題的發酵乳食品之製造方法，其特徵為對下述培養基接種乳酸菌並進行培養：該培養基係以乳為主成分，且添加有在培養結束時實質上全部被同化的量之葡萄糖與相對於葡萄糖以質量比計為2倍以上之果糖。
