Even though research work on MW heating of oil palm biomass was found in the literature, but little attention has been paid on the dielectric properties of oil palm biomass . They characterized dielectric properties of empty fruit bunch biomass. Sukari and Khalid (2009) detected dielectric properties of fresh oil palm fruit bunch at different moisture contents. No published article has yet revealed the details on dielectric properties of oil palm shell, oil palm fiber and palm shell biochar. Nevertheless,dielectric properties of wood and other solid materials can be found in the literature. Some of these studies reported that the dielectric properties are influenced by varying the frequency. Since biomass can be considered as woody material, some comparison can be made with the dielectric properties of the wood.