PURPOSE: To protect from overheating and damage due to heating by a method wherein a drying machine is equipped with the supplying device of steam, which supplies steam into a drying furnace upon stopping, interrupting or starting the drying of matters to be dried, and a discharging device, discharging the supplied steam.

CONSTITUTION: Far infrared ray emitting bodies 2, made of ceramics, are provided at the ceiling part and the bottom part of the inside of a drying furnace 1 and matters 3 to be dired are transferred from the entrance 11 of the matters to be dried into the drying furnace 1 continuously. Upon stopping or interrupting the transfer, a steam supplying valve 6 is opened to supply steam from the steam supplying port 8 of a steam pipeline 7 and diffuse it uniformly into the drying furnace 1 while a discharging fan 5 is operated at the same time. According to this operation, heated steam is induced uniformly from a discharging port near the matters 3 to be dried and is discharged out of a duct 10. Upon stopping the drying, the steam supplying valve 6 is closed and, then, the discharging fan 5 is stopped after the temperature of the far infrared ray emitting body 2 is reduced to a temperature which never affects the matters 3 to be dried. Accordingly, the overheating and the damage due to heating of the matters 3 to be dried can be prevented.