In order to provide a technique that allows to efficiently check validation of a structured document using single schema data corresponding to structured documents of different versions, a document verification apparatus, which includes a storage unit that stores single schema data corresponding to structured documents of different versions, and checks validation of structured document data using the single schema data, includes an input unit which inputs structured document data, a version determination unit which determines a version of the input structured document data, and a generation unit which reads out the single schema data from the storage unit, and generates a DOM tree of a schema corresponding to the determined version, and a verification unit which executes validation checking of the structured document based on the generated DOM tree.