Abstract: A fluorine-containing elastomer composition, which comprises (A) a fluorine-containing elastomer consisting of a copolymer comprising (a) tetrafluoroethylene, (b) perfluoro(alkyl vinyl ether) or perfluoro-(alkoxyalkyl vinyl ether), and (c) a cyano group-containing perfluorovinyl ether, (B) a cross-linking agent, and (C) spherical silica, wherein the spherical silica is high purity amorphous silica particles obtained by calcining metallic silica powders, and cooling the resulting vaporous silicon oxide. The present fluorine-containing elastomer composition can provide seal materials having distinguished processability, product appearance, plasma resistance, etc. by the cyano group-containing perfluoroelastomer having a good heat resistance and only silica as contained therein.