A process cartridge configured to be detachably attachable to a main body of an electrophotographic image forming apparatus, in which an occurrence of an image failure is suppressed, wherein the process cartridge includes an electrophotographic photosensitive member and a cleaning member arranged in contact with the electrophotographic photosensitive member, wherein an elastic deformation modulus of a surface layer of the electrophotographic photosensitive member is 35% or larger, and the cleaning member is formed of a urethane foam, wherein a density of the urethane foam is 200 to 500 kg/cm.sup.3, and a 25% compressive load of the urethane foam is 0.3 MPa or smaller.

Provided are a process cartridge and an electrophotographic apparatus each suppressed in fluctuation in charging potential at the time of its long-term use. The process cartridge includes: an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance; and a charging member configured to charge the electrophotographic photosensitive member, wherein an average of Martens hardnesses of the surface layer of the electrophotographic photosensitive member measured at a pushing force of 7 mN is 245 N/mm.sup.2 or more, and wherein in a core defined by three-dimensional surface texture standards (ISO 25178-2:2012) of the surface of the charging member, an average of Martens hardnesses measured at a pushing force of 0.04 mN is 2 N/mm.sup.2 or more and 20 N/mm.sup.2 or less, and an average of adhesivenesses measured with a scanning probe microscope in a field of view of 2-micrometer square is 70 mV or less.

Provided is an electrophotographic photosensitive member in which streaky image damage can be suppressed throughout long-term use in a low-temperature and low-humidity environment. An electrophotographic photosensitive member having a surface layer comprising a polyarylate and a polycarbonate, wherein the polyarylate has at least one structural unit selected from the group consisting of a structural unit represented by the following formula (1-1), a structural unit represented by the following formula (1-2) and a structural unit represented by the following formula (1-3), and the polycarbonate has a structural unit represented by the following formula (2-1).

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An electrophotographic photosensitive member includes a surface layer containing a charge transporting material and a specific polyester resin having a structure including a specific branched chain.

An electrophotographic photosensitive member includes a surface layer containing a charge transporting material and a polyester resin having a specific structure.

Provided is a process cartridge being detachably attachable onto a main body of an electrophotographic apparatus. The process cartridge includes an electrophotographic photosensitive member, a developing roller, and a toner-supplying roller. The developing roller and the toner-supplying roller are rotated so as to satisfy a particular velocity ratio so that the surface of the developing roller and the surface of the toner-supplying roller are opposite to each other at a contact position therebetween. The surface of the developing roller is a surface of an elastic layer, and the toner-supplying roller includes a shaft body and a resin layer formed on an outer peripheral surface of the shaft body. The electrophotographic photosensitive member includes a surface layer containing a polyarylate resin including a structural unit represented by the following formula (A1) and a structural unit represented by the following formula (A2).

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An electrophotographic photosensitive member including a surface layer containing a charge generating material and a polyester resin is provided. The polyester resin contains a structure having a 12- or higher-membered cycloalkylene group.

An image-forming apparatus with strontium titanate used as an external additive for a toner is provided, wherein the image-forming apparatus is an electrophotographic apparatus that has the durability of an electrophotographic photosensitive member maintained and is superior in transferability even under low-temperature/low-humidity conditions. An electrophotographic apparatus is provided, the electrophotographic apparatus including: an electrophotographic photosensitive member having a surface layer containing a resin X as a binder resin; a charging unit; an exposing unit; a developing unit; and a transferring unit, wherein the toner contains strontium titanate as an external additive, and the resin X contains a structural unit represented by Formula (1).

An image forming method in which a surface layer of an electrophotographic photosensitive member contains a compound having a specific structure in an amount of 0.1% to 10% by mass based on the total mass of the surface layer, and in a charged region of the surface of the electrophotographic photosensitive member charged in a charging step, a non-image forming region in which an electrostatic latent image is not formed is not irradiated with destaticizing light or is irradiated with reduced destaticizing light.

An electrophotographic member at least comprising: a base layer; and a surface layer on the base layer, wherein the surface layer comprises a binder resin, a tin oxide-containing particle, and at least one copolymer selected from the group consisting of a polyoxyethylene-polycaprolactone copolymer and a polyoxyethylene-polyvalerolactone copolymer; the binder resin comprises a (meth)acrylic resin; the copolymer has at least one functional group selected from the group consisting of a carboxy group and a phosphate group; and a content percentage of the particle in relation to the surface layer is 2.0% to 10.0% by volume.