The structured document management apparatus includes a document data accepting unit that accepts input of structured document data having a hierarchical logic structure; a structure guide data storage unit that stores structure guide data which is a summary of hierarchical structure information of the structured document data; a structure stream converting unit that syntax-analyzes the accepted structured document data, and converts the structure information in the structured document data into structure stream data as one-dimensional sequence data using the structure guide data; and a structure stream data storage unit that stores the converted structure stream data.