Korean food waste sludge was degraded by using a new thermal degradation method. In this system, radish contained waste food sludge as main portion was selected as a standard ma- terial. Products of thermal degradation were mainly composed of carbonized solid, small amounts of oil and methane. Total energy production was dependent on the reaction temper- ature. About 25-32% of solid in the radish was converted to carbonized solid in the thermal degradation of radish at 200℃. The heating values of the carbonized solid and the liquefied heavy oil were 4000-6000 cal/g and about 8000 cal/g respectively. Various catalysts were also examined to improve the carbonized solid used as energy source. Acid clay and Montmo- rillonite KSF catalysts showed the best results among the catalysts tested. From the energy balance, this thermal degradation process operated at 200℃ was a net energy producer.