NOVELTY - A fluorine-containing material comprises a rubber or gel obtained by crosslinking a curable composition comprising a linear polyfluoro compound containing two alkenyl groups per molecule and having a perfluoropolyether structure in its backbone, a fluorinated organopolysiloxane having greater than or equal to3 hydrogen atoms directly bonded to silicon atoms in a molecule, and a hydrosilylation catalyst.    USE - For use as fuel-related sealing materials in automobiles, power plants, chemical plants, ink jet printers, semiconductor manufacturing lines, analytical or scientific instruments, medical equipment, aircraft or fuel cells (all claimed).    ADVANTAGE - The rubber or gel material has improved dimethyl ether resistance, heat resistance, and freeze resistance.    DETAILED DESCRIPTION - A fluorine-containing material having a swelling degree of less than or equal to20% in dimethyl ether, comprises a rubber or gel obtained by crosslinking a curable composition comprising a linear polyfluoro compound containing two alkenyl groups per molecule and having a perfluoropolyether structure in its backbone, of formula CH2=CH-(X)p-CF(CF3)-(O-CF2-CF(CF3))m-O-(CF2)r-O-(CF(CF3)-CF2-O)n-CF(CF3)-(X')p-CH=CH2; a fluorinated organopolysiloxane having greater than or equal to3 hydrogen atoms directly bonded to silicon atoms in a molecule; and a hydrosilylation catalyst.    X=-CH2- or -Y-NR-CO-;    Y=-CH2- or dimethylphenylsilylene (Z);    R=Me or Ph;    X'=-CH2- or -CO-NR'-Y'-;    Y'=-CH2- or dimethylphenylsilylene (Z');    R'=Me or Ph;    p=0 or 1;    r=2-6;    m,n=0-200.    INDEPENDENT CLAIMS are also included for:    (1) an article comprising the fluorine-containing material;    (2) a pressure sensor for use in automobiles comprising a sensor section for detecting a pressure and generating an electric signal in response to the detected pressure value, and a protective member with chemical resistance covering the sensor section for protection, the protective member comprising the fluorine-containing material; and    (3) a fuel-related sealing material, which is a diaphragm, valve, O-ring, oil seal, gasket or packing, comprising the fluorine-containing material.