[Problem to Be Solved] A present invention provides a soy milk fermented substance with a taste and flavor or smooth physicality similar to that of yogurt obtained by fermenting milk with a lactic acid without applying processing treatment such as enzyme treatment or extraction treatment to soy milk which is a material and without adding a material such as a sugar source, even in a case where only Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus are employed as a lactic acid bacteria mixture starter at the time of making a fermented substance which employs soy milk as a material. [Means for Solving the Problem] The problem is solved by a soy milk fermented substance obtained by using a lactic acid bacteria mixture starter including: Streptococcus thermophilus which is capable of accumulating 0.4 g/L or more of fructose in the fermented substance when inoculated and cultured in soy milk； and Lactobacillus debrueckii subsp. bulgaricus which is capable of accumulating 0.4 g/L of D-lactic acid in the fermented substance when inoculated and cultured in soy milk.
