PURPOSE: To form a large preform without making a large scale of a spray chamber by constituting the spray chamber of a surrounding body having no bottom, providing the bottom part facing to the surface of a material to be coated and recovering an atomizing gas through a jacket.

CONSTITUTION: The material 20 to be coated is fitted below a frame base 21 and by executing a relative movement of rotation, ascent/descent and traveling, etc., to this material 20 to be coated respect to the spraying stream 10 flowing down from the tundish 3, the prescribed thickness of a coated layer is successively formed on the surface of the material 20 to be coated. Then, the used atomized gas is sucked to a jacket 23 from the chamber 22 and discharged to the air through a dust separator 27 and a suction fan 24.