The image forming apparatus including a heat roller fixing apparatus for heat-fixing an image obtained through development using toner to a recording medium, and a density sensor for detecting density of the image after the fixing, the image forming apparatus serving to adjust image density based on image density detected by the density sensor, in which the density sensor is disposed in a position where a temperature of the image being conveyed within a conveying path is equal to or lower than a coagulation temperature (melting point) of the toner.