PURPOSE: To obtain a soybean-fermented extract useful as a seasoning, food additive or health food.

CONSTITUTION: The objective food additive containing soybean-fermented extract is obtained by the following processes: 1st process: soybean swollen with water is subjected to a mixer together with water followed by heating into a soybean milk-like stock slurry; 2nd process: ERUZEN A bacteria (a kind of mixed microbes) is inoculated into the stock slurry followed by conducting a culture to prepare a culture fluid; 3rd process: ERUZEN B bacteria (another kind of mixed microbes) is inoculated into the stock slurry followed by conducting a culture to prepare another culture fluid; 4th process: the above two kinds of culture fluids are mixed together followed by agitation to prepare a combined culture fluid; 5th process: the combined culture fluid is heat-treated and then incorporated with alcohol followed by removing the solids contained.