An image forming apparatus, comprising: one or more image bearing members (20Y, 20C, 20M, 20BK) configured to form one or more toner images thereon at a predetermined process speed; a plurality of supporting rollers; a belt-like shaped medium configured to be charged with a charge voltage, to be rotatable, extended between the plurality of supporting rollers, and held in contact with the one or more image bearing members (20Y, 20C, 20M, 20BK); one or more primary transfer members (12Y, 12C, 12M, 12BK) corresponding to the one or more image bearing members (20Y, 20C, 20M, 20BK) on a one-to-one basis, and configured to sequentially transfer the one or more toner images formed on the one or more image bearing members (20Y, 20C, 20M, 20BK) onto the belt-like shaped medium at a position; a secondary transfer member configured to transfer the toner image carried on the belt-like shaped medium onto a recording sheet; at least one conductive roller connected to a ground and arranged upstream from the primary transfer member (12Y, 12C, 20M, 20BK) and downstream from the secondary transfer member in a rotation direction of the belt-like shaped medium, in contact with the belt-like shaped medium by a predetermined wrapping length wherein the belt-like shaped medium has a surface resistance in a range of from approximately 1x10 10 Ω to approximately 5x10 12 Ω, characterized in that a relationship Tb<X/Vb is satisfied, where Tb is an attenuation time period in units of second in which the charge voltage of the belt-like shaped medium decays from approximately 200 volts to 200/e volts, where e is a base of natural logarithm, X is the predetermined wrapping length in units of millimeter of the belt-like-shaped medium against the at least one conductive roller, and Vb is the predetermined process speed expressed in units of millimeters per second. one or more image bearing members (20Y, 20C, 20M, 20BK) configured to form one or more toner images thereon at a predetermined process speed; a plurality of supporting rollers; a belt-like shaped medium configured to be charged with a charge voltage, to be rotatable, extended between the plurality of supporting rollers, and held in contact with the one or more image bearing members (20Y, 20C, 20M, 20BK); one or more primary transfer members (12Y, 12C, 12M, 12BK) corresponding to the one or more image bearing members (20Y, 20C, 20M, 20BK) on a one-to-one basis, and configured to sequentially transfer the one or more toner images formed on the one or more image bearing members (20Y, 20C, 20M, 20BK) onto the belt-like shaped medium at a position; a secondary transfer member configured to transfer the toner image carried on the belt-like shaped medium onto a recording sheet; at least one conductive roller connected to a ground and arranged upstream from the primary transfer member (12Y, 12C, 20M, 20BK) and downstream from the secondary transfer member in a rotation direction of the belt-like shaped medium, in contact with the belt-like shaped medium by a predetermined wrapping length wherein the belt-like shaped medium has a surface resistance in a range of from approximately 1x10 10 Ω to approximately 5x10 12 Ω, characterized in that a relationship Tb<X/Vb is satisfied, where Tb is an attenuation time period in units of second in which the charge voltage of the belt-like shaped medium decays from approximately 200 volts to 200/e volts, where e is a base of natural logarithm, X is the predetermined wrapping length in units of millimeter of the belt-like-shaped medium against the at least one conductive roller, and Vb is the predetermined process speed expressed in units of millimeters per second.