A transfer apparatus having a photoconductor drum for holding thereon an image formed by toner charged with a negative polarity and a transfer roller disposed opposite the photoconductor drum, in which paper is fed to an area where the photoconductor drum and the transfer roller face each other and the toner image on the photoconductor drum is transferred to the paper by using a unidirectional transfer electric field formed by the transfer roller. The transfer roller also serves as charge supply control device for supplying a charge to the toner held on the photoconductor drum to thereby substantially neutralize the charge of the toner while retaining the negative polarity of the toner.