An image forming apparatus according to an exemplary embodiment of the invention includes a first image forming portion, a second image forming portion, a secondary transfer device, a transfer power supply, a controller.The first and second image forming portions include image bearing members, chargers, development devices, and transfer members.The first charger charges the first image bearing member in the same polarity as a predetermined polarity.The second charger for charging the second image bearing member in a polarity opposite the predetermined polarity.The controller controls the transfer power supply such that the transfer voltage applied to the second transfer member in the second image forming portion is not changed nor turned on and off in a period during which the toner image is transferred to the intermediate transfer member in the first image forming portion.