The microporosities of activated carbons were increased by two treatments. One involved depositing fine carbon particles on the activated carbons from pyrolyzing methanol accompanied by heating; and the other involved solely the heating of activated carbons in an inert atmosphere. The surface areas and pore volumes of the activated carbons increased by 43.43% and 75.75%, respectively, upon the former treatment, and as much as 61.96% and 100.82%, respectively, upon the latter treatment. Moreover, the number of pores with diameters ranging from 0.4 to 2.0 nm was appreciably magnified by both treatments, thereby giving rise to an increase in their microporosities. (C) 2005 Elsevier B.V. All rights reserved.