NOVELTY - A hardenable fluoro polyether-type rubber composition contains a linear fluoro polyether compound, silica-type filler, an organosilicon compound, and a hydrosilylation catalyst. The polyether compound has a perfluoro alkyl-ether structure and at least 2 alkenyl groups. The filler is surface-treated hydrophobically by dimethyldichlorosilane, and has a specific surface area of 50-300 m2/g and a bulk density of 30-80 g/l.    USE - For LIM molding and rubber articles, such as motor-vehicle components, components of chemical processing plants, components of inkjet printers, components of semiconductor production lines, components of physical and chemical analysis, components of medical machines, aircraft, fuel-cell components, diaphragms, valves, O-rings, oil seals, gaskets, packing, joints, and face seals (all claimed), e.g. diaphragms for fuel-regulators, pulsation dampers, oil-pressure indicator lamp switches, and exhaust gas recirculation, valves for canisters and power control, O-rings for quick connectors, injectors and fluid piping, gasket for cylinder heads, tent film materials, extrusion components, coating materials, copier roll materials, moisture-proof coating materials for electricity, potting materials for sensors, and laminated rubber cloth.    ADVANTAGE - The hardenable fluoro polyether-type rubber composition has excellent water repellency, oil repellency, solvent resistance, chemical resistance, weather resistance, and adhesion prevention property with respect to metal.    DETAILED DESCRIPTION - A hardenable fluoro polyether-type rubber composition contains (in weight parts) a linear fluoro polyether compound (100), a silica-type filler (10-50), an organosilicon compound, and a hydrosilylation catalyst. The polyether compound has a perfluoro alkyl-ether structure in the principal chain, and at least 2 alkenyl groups in the molecule. The silica-type filler is surface-treated hydrophobically by dimethyldichlorosilane, and has a specific surface area of 50-300 m2/g and a bulk density of 30-80 g/l. The organosilicon compound is present in an amount which enables hardening of the polyether compound, and has at least 2 hydrogen atoms coupled with the silicon atom.    An INDEPENDENT CLAIM is included for rubber articles consisting of the cured material of the hardenable fluoro polyether-type rubber composition.