An image filing apparatus prints a search (mark) sheet, on which the reduced image of the first page of a document stored on an optical magnetic disk is written, from a printer unit. When the printer unit cannot print the search sheet because no paper is available or the like, information indicating that the search sheet was not output is recorded on the magnetic optical disk is displayed on the operation screen of a touch panel display. A search sheet print key is also displayed on the operation screen. When the search sheet key is depressed, the not yet output search sheet is then printed.