PROBLEM TO BE SOLVED: To provide a filter medium having a simple structure and antibacterial property even in the inside. SOLUTION: Iodine is dissolved in potassium iodide aqueous solution. The iodine-dissolved solution is sprayed toward activated carbon so that potassium triiodide is adsorbed on the insides of the pores of the activated carbon. The potassium triiodide-adsorbed activated carbon and an aqueous emulsion (a binder) obtained by emulsifying a copolymer with a reactive emulsifier are dispersed in water. A nonwoven fabric is immersed in the dispersion liquid and then dried so that the potassium triiodide-adsorbed activated carbon is stuck to the nonwoven fabric. When the potassium triodide in the activated carbon is brought into contact with the water in the air or the like, iodine is eluted, which exhibits antibacterial property.
