Provided are methods of preparing an article in which a microporous layer is coated on a temporary carrier substrate and a substrate is then laminated to the microporous layer, prior to removing the temporary carrier substrate from the microporous layer. The application belongs to a source platform and is run on a target platform. Even when the electrolytic capacitor with the capacitor device is driven in a high-humidity atmosphere and a large amount of water penetrates into it, the capacitor is free from a trouble of dedoping, and therefore keeps its high voltage-proofness and leak current stability.