To provide a method of producing water-disintegrable paper capable of addressing a disadvantage of adhesion of a base-paper sheet to an embossing apparatus when the base-paper sheet impregnated with a water-soluble binder is embossed, achieving simple manufacturing and low manufacturing cost, and minimizing the likelihood of paper powder remaining on a dry surface of a cleaned object after use.To produce water-disintegrable paper, a base-paper sheet 2 in a non-wet state before a water-soluble binder is impregnated is embossed in order to form a bulking unit 17, made up of a plurality of uneven elements 12, on the base-paper sheet 2; a water-soluble binder solution 5 is sprayed to the base-paper sheet 2 having the bulking unit 17 formed, from outside of a face of the base-paper sheet 2 to impregnate the water-soluble binder solution 5 into the base-paper sheet 2; the base-paper sheet 2 impregnated with the water-soluble binder solution 5 is dried; the base-paper sheet 2 is folded after the drying; and an aqueous chemical solution is sprayed to the base-paper sheet 2 thus being folded to impregnate the aqueous chemical solution into the base-paper sheet 2.