The present invention provides a foam dispenser having a twice automatic cleaning function that automatically discharges a compressed air toward a mixing chamber, when releasing a pulled trigger lever, thereby improving convenience of work and providing economic advantages. The foam dispenser having a twice automatic cleaning function includes a main body 4 including a hose connection unit 34 and an air hose connector 42, a coupling end part formed at the other end thereof, a pair of fluid passageways 20, an air passageway 22, and a handle 3; a dispensing nozzle 6 connected to the coupling end part of the main body 4, has a mixing chamber 64; a separate-fluid supply unit 8 provided inside the main body 4 to open or close the fluid passageways 20; and an automatic cleaner 10 provided at a middle portion of the air passageway 22 to automatically open the air passageway 22.