PROBLEM TO BE SOLVED: To provide a method for producing an aduki bean fermented food product increasing the treatment efficiency of the protein of aduki beans whose improvement has been difficult heretofore by attaining the pulverization of aduki beans and the size enlargement of the pulverized powder thereof by swelling, and capable of easily and simply saccharifying the protein of adzuki beans.SOLUTION: Provided is a method for producing an aduki bean fermented food product comprising: an aduki bean pulverization step where aduki beans are pulverized so as to be the maximum particle diameter of 500 μm or lower; a heating-kneading step where the azuki bean raw material powder is kneaded while being heated at the inside of a two screw extruder to obtain an aduki bean swollen material; and an enzyme reaction step or fermentation step where diastatic enzyme is added to the aduki bean swollen material, or rice malt or aduki bean malt are added thereto, thus the aduki bean swollen material is liquefied or saccharified to obtain sugar derived from the azuki beans.SELECTED DRAWING: Figure 1【課題】小豆の粉砕とその粉砕粉の膨化による賦形化を図ることにより、従来改善の困難であった小豆のデンプンの処理効率を高め、容易かつ簡便に小豆のデンプンを糖化することが可能な小豆発酵食品の製造方法を提供する。【解決手段】小豆を粉砕して最大粒径を500μm以下とする小豆原料粉末を得る小豆粉砕工程と、小豆原料粉末を二軸エクストルーダー内にて加熱しながら混練して小豆混練物を得る加熱混練工程と、二軸エクストルーダーの吐出部からの吐出時に膨化させて小豆膨化物を得る膨化工程と、小豆膨化物に糖化酵素の添加、もしくは、米麹または小豆麹を添加して、小豆膨化物を液化及び糖化させて小豆由来の糖を得る酵素反応工程または発酵工程を備える。【選択図】図1