The present invention corrects and controls both short-term changes in the density and gradation of the obtained image due to changes in the environment and the like, and long-term changes in the density and gradation of the obtained image due to changes in the properties of the photosensitive member and the developer during a long use period using two kinds of density control operations. In first density control, a predetermined pattern is formed on a recording material via a visual-image forming process, and a contrast potential and an LUT (look-up table) for gamma conversion are set based on the value of density of the formed pattern and in a second density control, control is performed by controlling an amount of replenishment of a toner according to a first reference value, which is corrected based on the difference between the value of density of a pattern formed on a photosensitive drum and a second reference value, thereafter a pattern is formed on the photosensitive drum by driving the visual-image forming process with a parameter set in the first density control, and the first and second reference values are corrected based on the value of density of the formed pattern.