In an image forming device, an image forming engine is configured to form an image. The memory stores configuration information and confidential information. The controller is configured to operate based on the configuration information. In a case where a storage medium is connected to the input output interface, and the storage medium stores import configuration information and import instruction information, the controller imports the import configuration information as the configuration information to the memory by using the import instruction information, encrypts the import instruction information by using the confidential information, and stores the encrypted import instruction information in the storage medium. After the import configuration information is imported, the controller operates according to the import configuration information.