To provide a system capable of acquiring device information and controlling a magnetic tape device, without preparing in advance the information on a magnetic tape device on the driver side of the magnetic tape device.

A host computer 1 demands the magnetic tape device 2 to acquire the device support parameter by using a magnetic tape device driver 3. Then the magnetic tape device 2 takes out the device information from a device parameter storing section 22 to transmit it to the host computer 1. Judging whether or not the support format has been acquired from the magnetic tape device 2, and if yes, the magnetic tape device driver 3 registers the information to a device parameter information 30. Its content is reflected on a user input section 10, to show the user which device parameter is usable. Then the user selects and designates the device parameter from the user input section 10, to access the magnetic tape device 2.