PURPOSE: To make deodorizing device unnecessary, and to contrive simplification of a process and drastic cost reduction, by supplying organic waste and exhaust gas of a dryer, which run parallel with each other to a rotary kiln.

CONSTITUTION: A material 10 to be dried and heating air 12 are supplied to a dryer 11. Heating of air to be supplied to the dryer 11 is carried out indirectly through a heat exchanger 15 which makes combustion product gas 14 of a rotary kiln 18 into its heat source. Dried waste, that is, a dried material 17 and inflow air 16 containing a foul odor ingredient, which run parallel with each other are supplied into a rotary kiln 18 provided separately from the dryer 11 and both the foul odor ingredient and the dried material 17 are burnt. With this, it becomes unnecessary to install a deodorizing device for foul odor gas, and simplification of a process and drastic reduction of initial cost and running cost can be contrived.