PROBLEM TO BE SOLVED: To provide an active carbon having sufficient antimicrobial activity in addition to deodorizing and odor eliminating effects. SOLUTION: A treating liquid of 10 to 70 wt.% in iodine concentration is prepared by dissolving iodine into an aqueous potassium iodide solution. A iodine-potassium iodide electrolytic complex sticks to the surface and into the pores of the active carbon. The weight of deposition thereof is 10 to 60 wt.% per the anhydrous weight of the active carbon. When water contacts the electrolytic complex, the iodine elutes and the antimicrobial properties are exhibited by this iodine.