PURPOSE: To provide a trash character-detecting method for trash incineration furnace, which can accurately detect the character of trash such as moisture content, etc., before the trash is input in an incineration process zone, or at an extremely early stage after the input. CONSTITUTION: A trash incineration furnace is equipped with a push-in input mechanism 5 which pushes trash into the furnace from a push-in input port 2a, stoker type incineration process zone 6 which is located under the push-in input port 2a and incinerates the trash being fed by dropping from the push-in input port 2a while carrying it, and a radiation temperature measuring instrument 1, at a location which faces the push-in input port 2a from the downstream side of the incineration process zone 6. Then, the surface temperature of a cross section part of the trash, which is generated by a dropping from the push-in input port 2a to the incineration process zone 6 is detected by the radiation temperature measuring instrument 1, and the character of the trash is assumed based on a time variation of the surface temperature which is detected by the radiation temperature measuring instrument 1.