Activated carbon is the nonpolar containing carbon, activated by the steam (vapor) or chemicals. It is porous amorphous carbon that can be used in many fields of industry as the materials for decolorization, deodorization, recovery, separation, scavenging and so on. Until now, there are various types of raw materials to make activated carbon: chartype like woods, coconut and coal type like lignite, and hard coal. Thermoplastics can not be used to make activated carbon because the high volatile matter in them prevents char formation. For the case of thermoplastic aromatic polymer RPE (Refused Plastics Fuel), fabrication of activated carbon can be achieved using an aromatic polymer's special property, such as forming graphite structure. Activated carbons from EI (polyetherimide) showed high porosity in proportion to the high porosity. There were suprising results of high porosity and adsorption character, because nitricacid oxidation pretreatment offered an advantage of making more activation sites that gave such good porosity. Optimized conditions for the fabrication process of the activated carbon from such aromatic polymer as polyetherimide can be established as follows; carbonization temperature 750 ℃, activation temperature 950 ℃ and activation time 3 hr.