Abstract: Soy milk having a concentration of 10% to 15% is mixed with coagulant agent liquid that is obtained by dissolving a coagulant agent in warm water that is in an amount of 0.5 to 1.5 times a volume of the soy milk to obtain a curd. The coagulant agent coagulates protein contained in the soy milk. Thus obtained curd is dehydrated so that its water content to mass of the whole curd is within a range from 60% to 72% to obtain a processed soybean food of the present invention. In the present invention, the coagulant agent contains a compound selected from a group consisting of magnesium chloride and calcium chloride in a ratio of 0.2% to 0.5% of mass of the soy milk.