Provided is a method with which it is possible to suppress variations in the concentration of dialysate without limiting the amount prepared when preparing the dialysate as needed at the site of use. The standard solution filled article according to the present invention is a filled article consisting of a sealed container filled with a standard solution of a carbonate containing preparation. The sealed container is configured from a material having a gas barrier property. The sealed container is filled until the initial pH in the standard solution after filling becomes lower than the pH of the bicarbonate containing preparation to be prepared or up to the capacity limit of the sealed container or up to a state that does not exceed the capacity limit of the sealed container and leak.
