PURPOSE: To improve the vertical mixing efficiency by providing 1st and 2nd flames, a motor, a mixing tank, mixing blades, a setting member setting the slanting range of the mixing tank, and a fixing member fixing the mixing tank to an optional slanting angle in a specified arrangement.

CONSTITUTION: The flame 4 is kept in horizontal position, and the mixing tank 24 is fixed on a bottom plate 20. Mortar is thrown in the mixed tank 24 in which the mixing blades are provided. Then, the geared motor 18 is driven to rotate the mixing tank 24, and the kneading process is carried out. And, when a handle 9 is operated in the kneading process to slant the frame 4, the mortar in the mixing tank 24 is conveyed upward with the rotation of the mixing tank 24, fallen down by gravity, and kneaded again. And, by operating a handle 14, a motor supporting plate 17 is rotated around the center of an axis 12, and the mixing tank 24 is moved relatively to a mixing blades 29 to be set at an optimum position. Thus, the mortar in the mixed tank 24 is thoroughly kneaded in the vertical direction as well as in the radial direction.