The process of producing breadnut seed flour is composed of the following steps of selecting mature breadnut seeds, slicing the mature breadnut seeds halfway enough to provide small opening, blanching the sliced mature breadnut seeds in water with a predetermined temperature, oven roasting the blanched mature breadnut seeds at a predetermined temperature, peeling the roasted seeds by smashing to remove the outer and inner coating, oven drying the peeled roasted breadnut seeds at a predetermine temperature, pulverizing/ grinding the dried breadnut seeds, and packing in a zip bag.