To provide an image forming device without causing the reading impossibility and incorrect reading or the like of an identification code even when toner is insufficient, printing is performed with density lower than that in a conventional manner by saving toner, the identification code is printed with color toner, or the identification code is printed with a faint color so as to be made visually inconspicuous.

This device 1 is provided with a stuck quantity discriminating part 9 discriminating the stuck quantity of the toner to paper at a printing processing part 5, a color and density discriminating part 10 discriminating the printing color and printing density of the identification code at the printing processing part 5 and an identification code position setting part 11 setting the printing position of the identification code at the fixing start end position of the paper in the case of discriminating that the remaining quantity of the toner is reduced by the stuck quantity discriminating part 9 or in the case of discriminating that the identification code is printed so as to be colored or faint by the color and density discriminating part 10.