PURPOSE: To prevent spontaneous ignition, by arranging an infrared type temp. detector to a stack reclaimer while monitoring the temp. of stored coal simultaneously with the stacking or scraping work thereof.

CONSTITUTION: A stack reclaimer is moved on a track 5 and the temp. of the surface 3 of a stock of coal 4 is detected by the infrared detection camera provided to the outside of an operation room. Surface temp. distribution is subjected to color display on the display device and, when the part subjected to color display of 80W90°C is discovered, actions such as rolling press or discharge are directly taken to prevent spontaneous ignition.