Disclosed are: a fluorinated elastic copolymer which has excellent cross-linking reactivity and extrusion moldability and which can be cross-linked to produce a rubber having excellent compression permanent set deformation resistance, base resistance and oil resistance and is particularly suitable as a covering material for electric wires; and a process for producing the fluorinated elastic copolymer. Specifically disclosed is a fluorinated elastic copolymer produced by copolymerizing tetrafluoroethylene, propylene and optionally another monomer, wherein the molar ratio of a repeating unit (a) derived from tetrafluoroethylene to a repeating unit (b) derived from propylene in the fluorinated elastic copolymer (i.e., an (a)/(b) ratio) is 60/40 to 75/25, and wherein the content of a repeating unit (c) derived from the another monomer in the fluorinated elastic copolymer is 0 to 10 mol%.