PURPOSE: To facilitate the preparation and editing of a document by dividing an input document into elements and storing them, and displaying the respective divided elements distinctively.

CONSTITUTION: The document in object language is inputted to an input part 1 by using a keyboard, etc., and the document is edited by an editing part 3. The editing part 3 has a dividing means which divides the input document into the elements. The editing result of the editing part 3 is stored in a storage part 4. The respective elements divided by the dividing means of the editing part 3 are displayed distinctively at a display part 4. Further, the editing part has an editing means for editing in the elements.