A method of producing water-disintegrable paper, including: using a base-paper supplied with no water to emboss the base-paper sheet in a non-wet state to form a bulking unit, made up of a plurality of uneven elements, on the base-paper sheet; supplying the water-soluble binder to the base-paper sheet from outside of a face of the base-paper sheet after the embossing process to impregnate the water-soluble binder into the base-paper sheet; drying the base-paper sheet after the binder impregnation process; folding the base-paper sheet after the drying process; and supplying an aqueous chemical and/or a crosslinker to the base-paper sheet before or after the folding process to impregnate the aqueous chemical into the base-paper sheet.