A process for production of a flexible laminated sheet having one or more laminated bodies each provided with a metal foil formed on one side of a resin film, the process comprising a coating step in which a varnish containing a polyamic acid and a solvent is coated onto the metal foil to form a coated film, a holding step in which the coated film formed on the metal foil is held, a drying step in which at least a portion of the solvent in the varnish is removed to form a layer composed of a resin composition, and a resin film-forming step in which the layer composed of the resin composition is heated to form a resin film containing a polyimide resin. The conditions for each step from the coating step up to the resin film-forming step are adjusted based on a target for the content of metal elements in the resin film.