A composite metal foil in which the surface of a titanium foil or a titanium alloy foil is coated with an electrically conductive layer; in the composite metal foil, an electrically conductive film in which TiO is dispersed in an oxide film and the TiO composition ratio [I TiO /(I Ti +I TiO )] found from the maximum intensity of the diffraction peaks of TiO (I TiO ) and the maximum intensity of the diffraction peaks of metal titanium (I Ti ) out of the X-ray diffraction peaks of the surface of the titanium foil or the titanium alloy foil is 0.5% or more is formed on the surface of the titanium foil or the titanium alloy foil, and the electrically conductive layer consists of, in mass%, silver particles with an average particle size of not less than 10 nm and not more than 500 nm: 20% to 90%, a dispersant: 0.2% to 1.0%, and the balance: an acrylic resin or an epoxy resin, and has a thickness of 5 to 50 µm.