Use of a toner in an image forming apparatus comprising: an image carrier (40Y, 40C, 40M, 40Bk) that carries toner images; and an intermediate transfer member onto which the toner images are primarily transferred, sequentially from a first toner image, from the image carrier (40Y, 40C, 40M, 40Bk) to form a superposed toner image to be secondarily transferred onto a transfer member, wherein the intermediate transfer member is applied with different levels of primary transfer bias upon primary transfer of the toner images, a level of primary transfer bias applied upon primary transfer of the first toner image is higher than a level of primary transfer bias applied upon primary transfer of other toner images, and the primary transfer bias is sequentially lowered in level as the toner images are sequentially transferred onto the intermediate transfer member; characterised in that: the intermediate transfer member has a surface potential attenuation ratio such that residual potential of the intermediate transfer member applied with a voltage of 500 volts becomes equal to or lower than 250 volts after five seconds, wherein the toner includes toner base particles that contain a binding resin and a colorant; and the binding resin is a polyester resin; and polyester prepolymer and nonreactive polyester are simultaneously used as components that form the binding resin; and the toner is used in the image forming apparatus if the saturated implantation ratio of inorganic particulates, which is an additive externally added to the surface of the toner base particles, is equal to or greater than 40 percent. an image carrier (40Y, 40C, 40M, 40Bk) that carries toner images; and an intermediate transfer member onto which the toner images are primarily transferred, sequentially from a first toner image, from the image carrier (40Y, 40C, 40M, 40Bk) to form a superposed toner image to be secondarily transferred onto a transfer member, wherein the intermediate transfer member is applied with different levels of primary transfer bias upon primary transfer of the toner images, a level of primary transfer bias applied upon primary transfer of the first toner image is higher than a level of primary transfer bias applied upon primary transfer of other toner images, and the primary transfer bias is sequentially lowered in level as the toner images are sequentially transferred onto the intermediate transfer member; characterised in that: the intermediate transfer member has a surface potential attenuation ratio such that residual potential of the intermediate transfer member applied with a voltage of 500 volts becomes equal to or lower than 250 volts after five seconds, wherein the toner includes toner base particles that contain a binding resin and a colorant; and the binding resin is a polyester resin; and polyester prepolymer and nonreactive polyester are simultaneously used as components that form the binding resin; and the toner is used in the image forming apparatus if the saturated implantation ratio of inorganic particulates, which is an additive externally added to the surface of the toner base particles, is equal to or greater than 40 percent. the intermediate transfer member has a surface potential attenuation ratio such that residual potential of the intermediate transfer member applied with a voltage of 500 volts becomes equal to or lower than 250 volts after five seconds, wherein the toner includes toner base particles that contain a binding resin and a colorant; and the binding resin is a polyester resin; and polyester prepolymer and nonreactive polyester are simultaneously used as components that form the binding resin; and the toner is used in the image forming apparatus if the saturated implantation ratio of inorganic particulates, which is an additive externally added to the surface of the toner base particles, is equal to or greater than 40 percent.