The present inventors found that the natural flavor intrinsic to soybean is retained more than ever before when soybean is processed to prepare a processed soybean material having a specific lipid content, a dietary fiber content, an acid-soluble component content and a protein content, whereby the present problems were solved. More specifically, the processed soybean material of the present invention is such that, on a solid weight basis, (1) a content of lipid, extracted with a mixed organic solvent wherein a ratio of chloroform to methanol is 2:1, is 10 to 40% by weight, (2) a dietary fiber content is 5 to 40% by weight, (3) a potassium content is 1% by weight or less, (4) a protein content is 30 to 65% by weight, and (5) a sum of γ-conglycinin and 24 kDa protein is 2.4 times or less of lipoxygenase protein in soybean proteins.
