An image forming apparatus operates according to setting information, and includes a storage unit for storing the setting information; an interface for connecting a portable storage medium; a processing unit for reading/writing the setting information from/to the storage unit, and reading/writing the setting information from/to the portable storage medium via the interface, and a log creating unit for creating a first processing result log indicating a first processing result of a reading/writing process when the processing unit reads the setting information from the storage unit and writes the setting information in the portable storage medium, and storing the first processing result log, and creating a second processing result log indicating a second processing result of a reading/writing process when the processing unit reads the setting information from the portable storage medium and writes the setting information in the storage unit, and storing the second processing result log.