A tape management method capable of easily using a file on a virtual tape from a plurality of programs in a system virtually emulating a magnetic tape apparatus by a disk apparatus. When a use request is generated from other program to a volume of a virtual tape used by one program, a host computer generates and uses a volume of a temporal virtual tape and can thus permit the use of the temporal tape volume from a plurality of programs without drastically changing the specification of an existing tape interface. The volume of the virtual tape temporarily generated is generated in a virtual tape management table and a virtual tape file uses a file of the same type.