1. An image forming apparatus comprising: an image carrier; a charging component that charges the image carrier to a predetermined electrical potential; an exposing component that exposes the image carrier charged by the charging component with light and forms an electrostatic latent image on the image carrier; a developing component that develops the electrostatic latent image formed on the image carrier by the exposing component, using a developer in a state a biasing voltage is applied, the developer comprising a colorant and an external additive; a transfer component that transfers the developer image developed on the image carrier by the developing component onto a transfer body; a detecting component that detects a density of the developer image transferred onto the transfer body by the transfer component; a removing component that removes residual developer on the image carrier after the developer image has been transferred onto the transfer body by the transfer component; a first control component that controls the charging component, the exposing component, and the developing component such that a developer image representing a predetermined image is transferred onto the transfer body; a second control component that, after the first control component has controlled so as to develop the developer image representing the predetermined image formed a plurality of times in the same location on the image carrier by the exposing component, controls such that without performing exposure with the exposing component, the developer image, developed on the image carrier by the developing component applying a biasing voltage to the developer so as to adhere the developer to the image carrier including to the same location on the image carrier, is transferred to the transfer body; and a ghost image generation detecting component that detects whether or not a ghost image is generated by, after control by the second control component, comparing the density detected by the detecting component at a position of the transfer body corresponding to the same location of the image carrier with a reference density.