To provide a data output device capable of surely avoiding the leakage of a secret part while facilitating the management of data.

A controller 1 of the data output device acquires the data of document or image to be outputted and an identifier, which is added to these data, for specifying any data output device and investigates whether the identifier of the present data output device stored in a ROM 10 is contained in this identifier or not. When the identifier of the present data output device is contained in it, all the acquired data are printed out by a printer engine 14 but when the identifier of the present data output device is not contained, data in a non-output area designated to the acquired data are converted to blank data and printed out later by the printer engine 14.