A deactivation method is for a system including a communication terminal, a secure device, and a management apparatus. An identification number and communication identification code are notified to the management apparatus while the secure device is attached to the communication terminal. The management apparatus holds the identification number and the communication identification code by correlating them, acquires an identification number of a secure device to be deactivated, when instructed to deactivate the secure device by an authentic owner of a right to use the secure device, extracts the communication identification code in accordance with the identification number, and transmits the deactivation authentication code to an apparatus identified by the extracted communication identification code. If the communication terminal receives the deactivation authentication code while the secure device is attached to it, the secure device is deactivated.