Attributes can be set for an entire document, each chapter, and each page by using an entire document attribute, chapter attribute, and page attribute. When the print format of a chapter is set with a chapter attribute different from the entire document attribute, this chapter is printed in a print format complying with the chapter attribute. Similarly, when the print format of a page is set with a page attribute different from the entire document attribute or chapter attribute, this page is printed in the print format complying with the page attribute. In hierarchically displaying the document structure with a book, chapters, and pages, a predetermined icon is so added as to identify a chapter or page having a unique attribute.