NOVELTY - The apparatus has cylindrical stirring container (73) that is positioned facing vacuum arc vapor deposition source which deposits vapor deposition material. The alumina powder of 0.1-1 mm size is accommodated in the container and deposited with the material. The powder is stirred and pulverized by a stamp (85) comprising stamp head (87) that collides with bottom face (73a) of the container. The stamp head is repeatedly collided with the bottom face for pulverizing the powder, whose near edge is inclined in the direction separated from the container.    USE - Microparticles forming apparatus used in manufacture of fuel cell, catalyst carrier for car, gas sensor and for catalyst carrier of magnetic and dielectric materials.    ADVANTAGE - The vapor deposition material can be adhered to the alumina powder and formation of lump in the surface of the alumina powder can be avoided. Aggregation of powder in the catalyst support can be prevented and diameter of microparticles can be maintained.    DETAILED DESCRIPTION - The apparatus includes an opening in the container whose circular edge forms a slope inclined towards center shaft and has a level difference in predetermined location. An arm (89) is contacted at the circular edge and biased towards the bottom face. The stamp head is separated from the bottom face, when the arm reaches predetermined position along the slope. One end of the shaft is fixed to circumference of the container and other end of the shaft is inserted into the container. The scrapers (75a,75b) are contacted with the outer periphery of the bottom face and extended along the container whose rotational speed is increased as the vapor deposition period of the source is reduced. The collision period of the stamp head is increased as the discharge period of the source is reduced. An INDEPENDENT CLAIM is included for microparticles formation method involves depositing vapor deposition material on alumina powder accommodated in the container. The alumina powder is stirred within the container and pulverized. The rotational speed of the container is made faster as the quantity of the material is increased.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the scrapers and stamp of microparticles forming apparatus.    Stirring container (73)    Bottom face (73a)    Stamp (85)    Stamp head (87)    Arm (89)