A fluorecopolymer which comprises repeating units (a) based on
tetrafluoroethylene, repeating units (b) based on perfluoro(methyl vinyl
ether) and repeating units (c) based on perfluoro(propyl vinyl ether) in
a molar ratio of (a)/(b)/(c) of 40-70/3-57/3-57. The fluorocopolymer is a
perfluoroelastomer which is excellent in low temperature characteristics,
heat resistance and chemical resistance.