Provided is a document management system for managing document data by applying access restrictions to each metadata acquired by character recognition of document data to be managed. The mage forming apparatus acquires document data to be managed. The image-processing server performs character recognition of document data and acquires metadata. The image forming apparatus specifies metadata to be concealed in document data. The image forming apparatus receives a security setting, correlates a metadata name to be concealed with the security setting, and transmits the security setting together with document data to the image-processing server. The document-management server, in the case where there is an access request from a user for document data, allows access to the document data based on the security setting by not masking metadata for which there is access authority, and masking metadata for which there is no access authority.