1. An image forming device comprising: a transporting unit for transporting a document sheet by sheet to a specified reading position; a judging unit for judging whether a document transported by said transporting unit is an electronically tagged printed matter wherein image data is printed on an electronically tagged printing paper equipped with an electronic tag for storing electronic data in a certain part of the printing paper and said electronic tag stores image data printed on said electronically tagged printing paper; a reading unit for reading the image data from the electronic tag of the document which is judged as said electronically tagged printing matter by said judgment unit; and a printing unit for printing the image data read by said reading unit.