PURPOSE: To facilitate a take-out work for residual grains, by a method wherein a conveyance gutter, which can be opened and closed over a conveying stroke length after discharge of dried grains through rotation of a conveyance spiral is completed, is located to the lower part of a drying chamber in which grains are dried by draft as the grains flow down.

CONSTITUTION: Hot blast, which, with a drier 4 started, is generated through a burner located to a front wall panel 5, is sucked by an exauster, located to a rear wall panel 5 part, and flows across a drying chamber 1. Grains in the drier 4 is dried during flow down in the drying chamber 1, the grains are delivered to the lower part by a delivery valve 15, are discharged in a feed gutter through a conveyance spiral 2, and are conveyed to the upper part by means of an elevator 25. The grains are fed on a dispersing board 24 through the upper conveying spiral and are uniformly dispersed and returned in a storage chamber 22. When a moisture content in the grains is reduced to a specified value, the drier 4 is automatically brought into a stop through automatic control of a control box 8. The dried gains are discharged, and when the residual grains the conveying gutter 3 are cleaned, through control of the control box 8, a solenoid 7 is actuated, and a conveying plate 14 is opened to clean the residual grains in the conveying gutter 3.