The present invention provides an activated carbon which is used in an activated carbon electrode plate and a method of preparing an activated carbon electrode plate prepared using the same, in which the activated carbon electrode plate functions to remove gas and gaseous air pollutants at the same time. The method comprises the steps of: providing a raw pure activated carbon or an impurity-containing raw activated carbon; processing the raw activated carbon into a powdered activated carbon; treating the pores of the powdered activated carbon to maintain the pores; filtering the powdered activated carbon whose pores were treated, and mixing the filtered activated carbon with a binder to form a binder/activated carbon mixture; forming the binder/activated carbon mixture into a flowable activated carbon slurry; applying the activated carbon slurry to the surface of a conductive material; and drying the conductive material having the activated carbon slurry applied thereto.