The present invention provides a method for producing a food product containing nattokinase but containing little or none vitamin K2, comprising treating a Bacillus natto culture or culture supernatant with at least one coagulant selected from the group consisting of an inorganic coagulant and a cationic polymer coagulant (excluding chitosan). As the inorganic coagulant, calcium chloride or poly aluminum chloride is preferable, and their mixtures with a phosphorus coagulant are also preferably used. As the cationic polymer coagulant, cationic polysaccharides, hexamethylenediamine/epichlorohydrin polycondensates or dimethylamine/epichlorohydrin polycondensates are preferably used, and their mixtures with a polyacrylate are also preferably used.