Disclosed is a fluorine-containing copolymer having, as an essential component, a repeating unit derived from (a) a monomer having a fluoroalkyl group or a fluoroalkenyl group, (b) a monomer having an alkylene oxide group, (c) a monomer having an acetoacetyl group, (d) a monomer having a —CH(OH)—CH2—Cl group, and (e) a monomer having a —CH(OH)—CH2—OH group. In this fluorine-containing copolymer, the amounts of the monomer (a), the monomer (b), the monomer (c), the monomer (d) and the monomer (e) are 30-80 parts by weight, 1-30 parts by weight, 0.5-20 parts by weight, 0.5-20 parts by weight and 0.5-20 parts by weight, respectively. This fluorine-containing copolymer provides a base material such as a fiber product with excellent alcohol repellency, oil repellency, antifouling properties and soil release properties, while maintaining washing durability. This fluorine-containing copolymer serves as an active ingredient for a fluorine-containing fiber processing agent having soil release properties.