A frothing device (1) to froth milk, comprising a boiler (2) for producing vapor； a pump (11) for producing pressurized air； air-vapor delivering means (4) to deliver air and vapor to the milk (18)； the boiler (2) and the air pump (11) are connected to a tank (6) for separately feeding vapor and air to the mixing tank (6)； the tank is connected to the mentioned air-vapor delivering means (4) to deliver air and vapor to the beverage.
