The invention enables the control of the information in a storage unit in a user terminal, prevents data from leaking to unauthorized users and protects information in the user terminal. A management OS manages the input/output to/from a user work OS in the user terminal, identifies a control-triggering condition set by a management server, controls the information in the storage unit storing the user work OS-related information so that information leakage can be prevented, and it also backs up the user work OS-related information to the storage apparatus using the user work OS input/output information.