PROBLEM TO BE SOLVED: To solve the conventional problems of an antiallergic agent requiring that the mixing proportion of a soybean-fermented product requiring the fermentation by yeast must be high.SOLUTION: The antiallergic agent contains a lactic bacterium of a halophilic lactic bacterium having an ability for inducing the production of interleukin-12 (IL-12) and interferon-γ (INF-γ) of a Th1-type cytokine, and also having an ability for inhibiting the production of IgE.