The method for manufacturing electrically conductive macromolecules of the present invention is provided by reacting at least a monomer and an oxidizing agent to obtain electrically conductive macromolecules by a chemical polymerization method, the method including reacting the monomer and the oxidizing agent at least in a polymerizing vessel that contains a steam atmosphere. With this method, it is possible to obtain flat, electrically conductive macromolecules (10). Thus, it is possible to provide a method and an apparatus for manufacturing electrically conductive macromolecules in which it is possible to combine both low ESR and high capacity in a solid state electrolytic capacitor, realize low losses, and have low current leakage.