An integrated component for supplying and treating water for a dishwashing machine having a washing tank includes a monolithic body of plastics material, within which an inlet conduit for water, a chamber containing substances with water-softening properties, into which the inlet conduit leads, a salt-containing reservoir arranged in the lowermost portion of the body and having a filler tube for loading the salt and to be connected to the washing tank, a compartment for blowing out vapours having an inlet opening to be connected to the washing tank and an outlet opening, an outlet conduit of water, a conduit for supplying water to the reservoir to produce the brine, and a conduit connecting the reservoir to the chamber are defined. The monolithic body has at least one protrusion, to which a sealing gasket is associated, for the direct connection within an opening of corresponding shape of the washing tank.