METHOD FOR PRODUCING A DECONTAMINANT

[Object] To provide a filter medium that can fully exert a water purifying function even under a large filtration flow rate, and is difficult to cause a problem such as leakage from a water cleaner together with purified water.[Solving Means] A filter medium of the present invention includes a porous carbon material having a value of a specific surface area by a nitrogen BET method of 1 × 102 m2/g or more, a volume of fine pores by a BJH method of 0.3 cm3/g or more, and a particle size of 75 µm or more, alternatively, a porous carbon material having a value of a specific surface area by a nitrogen BET method of 1 × 102 m2/g or more, a total of volumes of fine pores having a diameter of from 1 × 10-9 m to 5 × 10-7 m, obtained by a non-localized density functional theory method, of 1.0 cm3/g or more, and a particle size of 75 µm or more.