A liquid dispenser device for being associated with a liquid reservoir (R), said device comprising: a chamber (10) provided with an inlet valve (5, 15), an outlet valve (32, 232), and a piston (3) that is suitable for varying the volume of the chamber; a liquid dispenser orifice (25); and a pusher (2) that is axially displaceable down and up between a rest position and a depressed position; the dispenser device being characterized in that the pusher (2) includes an elastically-deformable wall (212) that is thus displaceable relative to the remainder of the pusher, the piston (3) being in contact, at least momentarily, with the deformable wall (212), so as to be urged in displacement relative to the remainder of the pusher while the wall is being deformed, in such a manner as to open the outlet valve.