shows the ash contents and relative compositions of matter inorganic elements in the feedstocks. To remove the inorganic matter, raw EFB was washed with water using a soxhlet extractor for 24 h. The ash content was decreased from 4.2% to 1.2% and the 8.9% of EFB was lost when it was washed with water, therefore, it is regarded that a part of the inorganic matter exists in a form which is soluble in water. After washing, the composition of Cl decreased to almost zero, while that of K also decreased significantly. On the other hand, the compositions of Al, Si, Ca and Fe increased. From these observations, it can be assumed that Cl and K become bonded with the components which are more soluble in water as compared to the other elements.