NOVELTY - A composite metal foil comprises electroconductive layer coated on surface of a titanium foil or titanium alloy foil, and conductive film with titanium oxide structure rate calculated as the ratio of titanium oxide diffraction peak maximum intensity (ITiO) with respect to the total of titanium oxide diffraction peak maximum intensity (ITiO) and titanium metal diffraction peak maximum intensity (ITi), of 0.5% or more, and titanium oxide dispersed in an oxide film is formed on the surface of the titanium foil or titanium alloy foil.    USE - Composite metal foil is used for separator for fuel cell (all claimed) used as electric power drive source of motor vehicle.    ADVANTAGE - The composite metal foil has low contact resistance, and excellent corrosion resistance with respect to fluorine ion, adhesiveness of titanium foil and electroconductive layer, and fatigue load resistance caused by thermal expansion and contraction in environment of fuel cell by repeated electric power generation.    DETAILED DESCRIPTION - A composite metal foil comprises electroconductive layer coated on the surface of a titanium foil or titanium alloy foil, and a conductive film with titanium oxide structure rate calculated at X-ray diffraction peak of the surface of the titanium foil or titanium alloy foil as the ratio of titanium oxide diffraction peak maximum intensity (ITiO) with respect to the total of titanium oxide diffraction peak maximum intensity (ITiO) and titanium metal diffraction peak maximum intensity (ITi), of 0.5% or more, and titanium oxide dispersed in an oxide film is formed on the surface of the titanium foil or titanium alloy foil. The electroconductive layer comprises 20-90 %mass silver particles having average particle size of 10-500 nm and 0.2-1 %mass dispersing agent, and remainder of acrylic resin or epoxy resin, and has thickness of 5-50 mu m. An INDEPENDENT CLAIM is included for manufacture of composite metal foil, which involves immersing titanium foil or titanium-alloy foil in non-oxidizing acid, carrying out cathode electrolytic treatment, heat-treating the resultant product, and forming electroconductive layer.