A color deviation detection device for a color image forming device which prevents the occurrence of color deviation that is attributable to the fact that the precision of color deviation detection is low, the replacement of photosensitive bodies or developing devices is itself a cause of fluctuation in the color deviation, and the precision of the part before and after replacement is slightly different. In the color deviation detection device, the spacing between marks of the reference color and other colors, the spacing between marks of the same color and the spacing between mark sets are set as the spacing between marks within the mark sets and the spacing between mark sets, so that when the amount of color deviation is calculated for a synthesized wave comprising two or more driving irregularity frequencies that are generated by the image carrying body driving system and the transfer driving system, the calculation error caused by this synthesized wave is within a range that allows correction of the deviation of the image of a plurality of colors.