A kneading machine is provided having a kneading tank with kneading rotors therein and a stocking opening. The kneading machine may also include a pressurizing lid for opening and closing the kneading tank and an inner-pressure cover. The kneading tank is capable of inverting in a range of 90° to 120° for discharging the kneaded materials. A front wall defining the stocking opening may be attached so as to be suspended downward from the kneading tank by a hinge when the kneading tank is inverted. The kneading machine may also include a capturing apparatus with a duct connected to the inner-pressure cover to capture powder compound jetted into the inner-pressure cover, and the powder compound captured in a filter of the capturing apparatus can be collected into the kneading tank.