Provided is a process cartridge including a developing roller having a resin layer formed on an outer surface of a conductive substrate, wherein the resin layer of the developing roller contains a polyurethane having a polycarbonate structure, when a specific AC voltage is applied to an outer surface of the developing roller while being varied within a specific frequency range, an impedance at a certain frequency is 1.010.sup.6 or more, when a corona discharger is relatively moved along an axial direction of the developing roller at a speed of 400 mm/sec to charge the outer surface of the developing roller, and a potential of the outer surface is measured 0.06 seconds after the outer surface passes through a grid portion, a maximum value of the potential is less than 20.0 V.

A developing apparatus including: a toner configured to have toner particle and external additive; a toner carrying member configured to carry the toner; and an charge injection member configured to inject electric charge into the toner, in which the external additive contain titanium atom-containing fine particles containing a compound containing titanium atoms, a presence ratio of the titanium atoms is 0.05 to 4.00 atomic % when a surface of the toner is measured using X-ray photoelectron spectroscopy, the toner carrying member is a developing roller having a substrate having a conductive outer surface and a resin layer on the outer surface of the substrate, impedance of the developing roller measured under specific conditions is 1.0010.sup.6 or more, and a maximum value of a surface potential measured under specific conditions is less than 20.0 V.

A developing roller includes a substrate having a conductive outer surface and a conductive layer on the outer surface of the substrate, an outer surface of the developing roller is formed of at least a first region and a second region having higher conductivity than the first region, the first region and the second region are placed adjacent to each other, the first region is placed on an outer surface of the conductive layer, the outer surface of the developing roller has an impedance of 1.010.sup.6 or more, and a potential of the outer surface of the developing roller satisfies a predetermined relationship.

A developing apparatus including: a toner having a toner particle and an external additive; a toner carrying member used for carrying the toner; and a charging member used for injecting charge into the toner, in which the external additive includes a fine particle A and a fine particle B, the fine particle A is at least one fine particle selected from a group consisting of a silica fine particle and a silicone fine particle, the fine particle B is a specific conductive fine particle, the toner carrying member is a developing roller having: a substrate having an outer surface having conductivity; and a resin layer on the outer surface of the substrate, and impedance of the outer surface of the developing roller and a maximum value of electric potential of the outer surface are in specific ranges.