which sandwich the intermediate transfer belt 31 are not apart becomes long a track sandwiched by the members remains as the unevenness in the transfer accepting body if the primary transfer is performed to a portion where this unevenness occurs u201c deletion white space on a colored background u201d by a transfer failure of the toner image in the portion where the unevenness occurs may be produced it is conceivable that this is because the coulomb 39 s force to draw the toner to the transfer accepting body side is lowered due to the unevenness of the surface of the transfer accepting body and so in the image forming apparatus 1 the optical sensor section 6 which is used to control the density of toner is used to detect the unevenness on the intermediate transfer belt and also by the method which will be explained in the following u201c the deletion white space on a colored background u201d by the unevenness is suppressed fig3 is a graph illustrating an output signal from an light receiving sensor which receives a reflected light reflected from a surface of an intermediate transfer belt firstly in the image forming apparatus 1 according to the present invention in order to check how an output signal from the light receiving sensor changes if there is the unevenness on the surface of the intermediate transfer belt 31 a condition is made in which a same.