To allow a user to smoothly obtain desired information by displaying the next key word candidate on the same screen at the same time of displaying a retrieving result matched with an inputted key word, and performing a narrowing by a key word based on an actual result thereby executing retrieval support matched with the times.

When the user inputs a key word and depressing a retrieving key, matching is executed with the key word section of an index file 13 based on the key word. When there is a key word matched with the inputted key word, the address of the pertinent address number of a retrieving result file 14 is displayed on the screen of a terminal 11 based on the number of a corresponding section. At the same time of it, the key word of the pertinent key word link number of a key word link file 15 is displayed on the screen of the terminal 11 and a section for inputting the next key word is simultaneously displayed. When there is not a key word matched with the inputted key word, the absence of pertinent information is displayed on the screen of the terminal 11.