The present invention provides use of an antioxidant for manufacture of a device for selectively removing HLA-DR-positive monocytes, which selectively removes HLA-DR-positive monocytes from blood comprising an anticoagulant, wherein the device for selectively removing HLA-DR-positive monocytes comprises a cell removal filter formed by a surface-unmodified polyester non-woven fabric, the cell removal filter is filled with a filling solution comprising an antioxidant and is subjected to radiation sterilization, the anticoagulant is at least one selected from the group consisting of citric acid and a salt thereof, and the antioxidant is at least one selected from the group consisting of sodium pyrosulfite, potassium pyrosulfite, sodium thiosulfate, sodium hydrogen sulfite, sodium sulfite, hypophosphorous acid, ascorbic acid, and an ascorbic acid derivative.
