A foamer dispenser, comprising: a base cap held by a mouth of a container; two pumps (2, 3) suspended from and held to the mouth of the container by the base cap, the two pumps (2, 3) comprising one pump configured to suck, pressurize, and pump a content medium and the other pump configured to suck, pressurize, and pump air; and a nozzle head configured to mix the content medium and the air pumped from the corresponding pumps (2, 3) and to foam the mixture of the content medium and the air by a foaming member disposed inside the nozzle head to be dispensed to outside through an internal passage, wherein the pump configured to suck, pressurize, and pump the content medium includes: a small-diameter tubular body provided in a bottom portion thereof with a suction port for inflow of the content medium; a hollow piston disposed in abutment with an inner circumferential surface of the small-diameter tubular body and configured to slide toward the bottom portion of the small-diameter tubular body to pressurize and pump the content medium that is present in the small-diameter tubular body; and a hollow stem including an inner passage through which the content medium pumped from the hollow piston is supplied to the nozzle head and also including a flange protruding from an outer circumferential surface of the hollow stem outward in a radial direction, the pump configured to suck, pressurize, and pump the air includes: a large-diameter tubular body including a bottom portion coupled integrally to the small-diameter tubular body; an air piston disposed in abutment with an inner circumferential surface of the large-diameter tubular body and configured to slide toward the bottom portion of the large-diameter tubular body to pressurize and pump the air that is present in the large-diameter tubular body; and a tubular guide that is coupled integrally to the air piston, that surrounds the hollow stem to define a first airway between the hollow stem and the tubular guide, that holds the hollow stem in a manner such that the hollow stem is slidable, and that is configured to come out of abutment with the flange in response to downward sliding of the hollow stem, thereby opening the first airway to supply the air pumped by the air piston to the nozzle head through the first airway, and the flange is provided with: an outer annular wall protruding upward from an outer edge of the flange; characterized in that: the flange is further provided with a guide rib (r) located on an outer side of the tubular guide in the radial direction and configured to be guided by the tubular guide during sliding of the hollow stem. a base cap held by a mouth of a container; two pumps (2, 3) suspended from and held to the mouth of the container by the base cap, the two pumps (2, 3) comprising one pump configured to suck, pressurize, and pump a content medium and the other pump configured to suck, pressurize, and pump air; and a nozzle head configured to mix the content medium and the air pumped from the corresponding pumps (2, 3) and to foam the mixture of the content medium and the air by a foaming member disposed inside the nozzle head to be dispensed to outside through an internal passage, wherein the pump configured to suck, pressurize, and pump the content medium includes: a small-diameter tubular body provided in a bottom portion thereof with a suction port for inflow of the content medium; a hollow piston disposed in abutment with an inner circumferential surface of the small-diameter tubular body and configured to slide toward the bottom portion of the small-diameter tubular body to pressurize and pump the content medium that is present in the small-diameter tubular body; and a hollow stem including an inner passage through which the content medium pumped from the hollow piston is supplied to the nozzle head and also including a flange protruding from an outer circumferential surface of the hollow stem outward in a radial direction, the pump configured to suck, pressurize, and pump the air includes: a large-diameter tubular body including a bottom portion coupled integrally to the small-diameter tubular body; an air piston disposed in abutment with an inner circumferential surface of the large-diameter tubular body and configured to slide toward the bottom portion of the large-diameter tubular body to pressurize and pump the air that is present in the large-diameter tubular body; and a tubular guide that is coupled integrally to the air piston, that surrounds the hollow stem to define a first airway between the hollow stem and the tubular guide, that holds the hollow stem in a manner such that the hollow stem is slidable, and that is configured to come out of abutment with the flange in response to downward sliding of the hollow stem, thereby opening the first airway to supply the air pumped by the air piston to the nozzle head through the first airway, and the flange is provided with: an outer annular wall protruding upward from an outer edge of the flange; characterized in that: the flange is further provided with a guide rib (r) located on an outer side of the tubular guide in the radial direction and configured to be guided by the tubular guide during sliding of the hollow stem.