A machine for use in granulation, coating, mixing, drying etc. of powdery or granular raw materials such as medicine or foods etc. The machine is comprised of a casing for containing raw materials, a rotator for tumbling and giving centrifugal force to the material in the casing rotatable horizontally in the casing and at least one disintegrator provided above the rotator for subdividing undesirously large particles. At least one agitator is provided above the rotator for agitating and kneading materials to be granulated or coated. The rotator is movable or fixed in vertical position, and an annular slit is formed between an annular slit forming ring or inner wall of the casing and outer periphery of the rotator. The slit forming ring is movable or fixed in vertical position. At least one ventilating portion is formed on at least one portion of the rotator, and a gas flow rate adjusting mechanism is provided for controlling flow rate of gas passed through the ventilating portion.