A packaging and filling machine that is capable of easily preforming with the forming flaps by keeping the pressure of the filled liquid food in the tube at positive pressure, capable of preventing the pressure of the liquid food from dropping to negative pressure, even if the pressure of the liquid food decreases due to the change in the liquid food pressure, and capable of preventing outside atmosphere materials from invading into the tube.A pressure flange fixed on a periphery of the filling pipe absorbs fluctuation of the pressure of the liquid food in the tube below the pressure flange, and prevents the liquid food pressure from dropping to negative pressure to keep the pressure of the liquid food in the tube below the pressure flange at a positive pressure.