PURPOSE: To provide a diffusing device which can uniformly distribute cereals into the quality regulating chamber of a drier, by a method wherein a rotary convey screw and spring-out vanes, located at given intervals in a conveying direction, are rotated within a horizontal convey conduit having the one side which is open.

CONSTITUTION: Cereals, lifted by an elevator and fed in a conveying conduit 1, is continuously conveyed as shown by an arrow mark (b) by means of a rotary convey screw 2. In which case, spring-out vanes 3, disposed at given intervals, are also rotated, and thereby the cereals are caused to be sprang out directly to a quality regulating chamber from an open side part (a) of a convey conduit 1. The spring-out vanes 3 are constituted such that the spring-out vane at the start terminal of conveyance has a minimum vane area, and the area of the vane of the point on the convey screw increases the further close to the end terminal side this point is situated. This constitution enables cereals to be evenly sprang out throughout the entire open part (a) and be distributed uniformly.