An image forming apparatus of the present invention includes an image forming unit to form a developer image on an image carrier, a transfer unit to transfer a developer image on an image receiving medium, a conveyor belt provided in contact with the transfer unit to carry and convey the image receiving medium with a developer image transferred by the transfer unit and a voltage applying portion to apply voltage to the transfer unit. This image forming apparatus further includes a controller to control voltage to be applied by the voltage applying portion to at least either one of the leading edge portion and the trailing edge portion of the image receiving medium in the direction conveyed by the conveyor belt so that it becomes higher than voltage to be applied to the middle portion in the conveying direction of the image receiving medium.