A color image forming apparatus includes: a multiple number of process printing units, each having an photoreceptor drum for supporting a developer image formed with a developer corresponding to each color of color-separated image information; a transfer belt to which the developer images formed on the photoreceptor drums are transferred; and a transfer roller for transferring the transferred developer image to recording paper, and is constructed so that the transfer belt is formed of a material which makes it possible for the transfer belt to attenuate the voltage charged thereon by 1,000 V or greater while it moves from a position where secondary transfer is performed to a position where the initial primary transfer is performed.