A device for regulating a water flow rate for a faucet body, comprising: a water inlet and outlet, a closing plug having a metal part sliding inside a cylindrical chamber having a diameter substantially equal to a diameter of the plug; a pushbutton comprising a magnet associated with the metal part, the pushbutton able to be operated so as to displace the magnet and the closing plug along an axis of the cylindrical chamber, into two different stable directions, corresponding to opening or closing of the water flow. The device comprises a first disk with a hole; a second disk, coaxial with the first disk and comprising at least another hole; the second disk axially rotatable relative to the first disk, and the flow rate of the water corresponds to a cross-section of a water passage through the second holes, the cross-section associated with an angular displacement of the disks.