A manually operated liquid foaming dispenser is attached to the top of a container of liquid and is manually vertically reciprocated to dispense the liquid from the container as a foam. The dispenser includes a liquid pump chamber and an air pump chamber that respectively pump liquid and air under pressure to a discharge passage of the pump where the liquid and air are mixed, generating the foam dispensed from the dispenser. The air pump chamber has a tube valve controlling the discharge of air from the air pump to the discharge passage, and the air pump chamber is charged with air by opening the air pump chamber to the exterior environment of the dispenser.