In this study, the activated carbon fiber (ACF), on which Ag had been introduced by an electroplating technique, was used to remove NO. Surface properties of the ACF were determined by X-ray diffraction (XRD) and scanning electron microscope (SEM). N₂ adsorption isotherms at 77 K were investigated by BET and t-plot methods to characterize specific surface areas and pore volumes, and NO removal efficiency was confirmed by gas chromatographic technique. As experimental results, Ag content on the ACF increased with plating time. However, adsorption properties such as BET specific surface area and total pore volume were somewhat decreased in the presence of silver. NO removal efficiency of all Ag-ACF was higher than that with untreated ACF and increased with Ag content. However, decrease in the extent of NO removal was shown in the excessively plated ACF, which might be associated with the blocking of micropores in the carbon; therefore, an optimal Ag content exists in the presence of initially-well-developed micropores to lead increase in efficient NO removal ability of the ACF.