A data communication device for storing image data input by scanning an original document in an external storage device includes a scanner, an inputting unit, a log-in processing unit, and a processing unit. The scanner scans an original document to input image data. The inputting unit inputs identification information. The log-in processing unit causes a user who is authenticated based on the input identification information to log into the data communication device. The processing unit performs data processing to store image data input by the scanner in an external storage device which is accessible based on the input identification information.