A composite metal foil is provided comprising a porous metal foil comprising a two-dimensional network structure composed of a metal fiber, and a primer provided on at least a part of the interior and/or periphery of pores of the porous metal foil. According to the present invention, it is possible to obtain a composite metal foil which has a desired function imparted by a primer in addition to superior properties derived from a porous metal foil, in a highly productive and cost effective manner that is suited for continuous production.