To improve processing efficiency and form an article to be processed into a uniform powdered one.

A rotary shaft 29 is rotatably provided in a drying tank 1, and a stirring member 31 and a press member 36 are mounted on the rotary shaft 29 and are made integrally rotatable. The stirring member 31 includes a stirring blade 34, and the press member 36 includes a plurality of rollers 41 rotating along an internal surface of the drying tank 1. Once the stirring member 31 and the press member 36 are rotated integrally with the rotary shaft 29, an article to be processed in the drying tank 1 is stirred with the stirring blade 34 and is moved in the direction of an inner wall surface of the drying tank 1 under centrifugal force. Further, the article is stirred with rotation of a roller 41 at that position and is crushed into powder between the roller 41 and the inner wall surface of the drying tank 1. The article is heated with a heating medium in such a process and is dried.