An apparatus for forming and dispensing portions of soap foam or lather is provided with a double-acting compressed air membrane pump for generating compressed air and with a soap solution dosing pump. Both pumps are operated by means of a single lever which need only be pressed in a single direction, the return motion to the initial position being effected by a return spring. The forward actuation of the lever causes soap foam or lather to be formed in a mixing chamber. The return motion of the lever dispenses a dose of soap foam or lather through a dispensing aperture. In order to obtain a double-acting pump action of the membrane of the membrane pump, inlet valves and and outlet valves are employed. One of the outlet valves assists in the generation of the soap foam in the mixing chamber. The other outlet valve then assists in ejecting a portion of the soap foam through the dispensing aperture during the return motion of the lever.