Disclosed is a water-repellent oil-repellent agent which contains a fluorine-containing copolymer as an active ingredient. The fluorine-containing copolymer contains, as copolymerization units, (A) at least one of perfluoroalkylalkyl acrylates represented by the following general formula: CnF2n+1CmH2mOCOCR=CH2 (wherein R represents a hydrogen atom or a methyl group, n represents 4, 5 or 6, and m represents 1, 2, 3 or 4) or corresponding methacrylates, (B) a benzyl acrylate or a benzyl methacrylate, (C) a fluorine-free polymerizable monomer other than benzyl acrylates and benzyl methacrylates and (D) a crosslinkable group-containing polymerizable monomer.