A transfer device includes an intermediate transfer belt having a surface to which a toner image may be transferred and solid lubricant particles are attached, a primary transfer member performing primary transfer of a toner image to the surface of the intermediate transfer belt, a secondary transfer member performing secondary transfer of the toner image to a surface of a recording medium, and a detection device detecting a density of the toner image and has a light irradiation unit irradiating the surface of the intermediate transfer belt and a light receiving unit receiving reflected light, in which a relationship between a volume-average particle size A (nm) of the solid lubricant particles attached to the surface of the intermediate transfer belt and a wavelength B (nm) of the light radiated from the light irradiation unit satisfies the following Expression: Expression 1:B>A×8.6+300.