A control section attaches a reprinting data mark to FAX image data received in a “Replace Toner” state and then stores the data. Then, a user is prompted to check whether an image of the FAX image data with the reprinting data mark printed most recently has been outputted appropriately. In case of appropriate output, all the FAX image data pieces with the reprinting data marks stored in a storage section are deleted. In contrast, in case of inappropriate output, the FAX image data is stored intact as reprinting data.