Aimed is to provide a chemical filter that is made of high-strength filter materials and can maintain the ability of removing the ionic gas pollutants for a long term. The chemical filter obtained byfabricating a chemical filter material, the chemical filter material being a woven or nonwoven fabric formed from a hydroxyl group-containing organic fiber, the hydroxyl group-containing organic fibercontaining cation exchange groups introduced by radiation graft polymerization, the chemical filter material having an ion-exchange capacity of 400 meq/m2 or more with respect to the cation exchangegroups, and the chemical filter material having a tensile strength of 5 to 20 N/15 mm.