The image forming apparatus includes a CPU capable of executing neutralization control in which, prior to image formation, a potential difference between a voltage applied to a transfer roller by a transfer power supply and a voltage applied to a neutralization needle by a neutralization power supply is gradually increased, and a value of the potential difference when the value detected by the neutralization current meter exceeds a threshold is stored, and in which, during image formation, a value of the voltage applied by the neutralization power supply is controlled based on the stored potential difference and the value of an image formation voltage applied by the transfer power supply.