A document information processing apparatus is obtained in which there is no need to provide the consistency of management between the instances of documents and their metadata, that is, there is no fear that inconsistency in management might be caused, thereby eliminating the possibility of loading the system, which would otherwise result from the provision of managerial consistency, as well as making it possible to improve their versatility. The apparatus includes a document input and output section that is able to at least input or output a document as an image data, an operation timing detection section that detects predetermined operation timing for the document, a metadata acquisition section that acquires metadata of the document based on the operation timing, and a metadata description section that describes the metadata in a predetermined format based on instance data of the document at predetermined timing with respect to the input or output of the document.