An electroconductive elastic body includes: a cross-linked product of a first ionic electro-conductive rubber, a cross-linked product of a second ionic electro-conductive rubber, and at least one of a fatty acid and a fatty acid metal salt; wherein the electroconductive elastic body has a matrix that includes the cross-linked product of the first ionic electro-conductive rubber, and a domain that includes the cross-linked product of the second ionic electro-conductive rubber;

the cross-linked product of the second ionic electro-conductive rubber includes a polyether skeleton; an electrical resistance of the domain is lower than an electrical resistance of the matrix; in a waveform separation profile of the elastic body as obtained by a small-angle X-ray scattering method, A2 and A1 satisfy a relationship expressed by the following expression (1):

0.005≤(A2×C2/A1×C1)≤0.030  (1).

An electro-conductive member for an electrophotographic image forming apparatus for which a change in resistance value is small even when a large current is applied at a high voltage for a long period of time is provided. The electro-conductive member includes a support having an electro-conductive outer surface and an electro-conductive layer on the outer surface of the support, in which the electro-conductive layer has a matrix including a cross-linked product of a first rubber and domains dispersed in the matrix, the domains include a cross-linked product of a second rubber different from the first rubber and an electrically conductive agent, and the cross-linked product of the second rubber has, in a molecule, a structural unit represented by Structural Formula (I).

[—(CH.sub.2).sub.n—O—]  Structural Formula (I)

In Structural Formula (I), n is an integer of 1 to 3.

An elastic member includes a substrate, and a single-layer elastic layer provided on the substrate. An elastic modulus of the elastic layer at a distortion of 10% is 0.15 MPa or more. When in the elastic layer, a thickness from the surface on a side opposite to the substrate to the substrate-side surface is t, and when in the elastic layer, a region from the surface on the side opposite to the substrate to a position at a depth of t/2.125 is referred to as an “outer surface portion”, and a region from the substrate-side surface to the position at a depth of t/2.125 is referred to as an “inner surface portion”, a ratio (elastic modulus of outer surface portion/elastic modulus of inner surface portion) of an elastic modulus of the outer surface portion to an elastic modulus of the inner surface portion is 0.8 or less.

There is provided a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including an electrophotographic photosensitive member and a charging member, wherein an outer surface of the charging member is composed of at least a matrix and at least a part of domains, a volume resistivity of the matrix is 1.0×10.sup.5 times or more of a volume resistivity of the domain, an average value Sd of circle equivalent diameters of the domains observed on the outer surface of the charging member is in a predetermined range, the electrophotographic photosensitive member contains a support, a photosensitive layer, and a protective layer in this order and when a surface roughness of the protective layer is measured, each of a protruding valley portion Rvk, a load length ratio Mr2, and Sd/Rvk is in a predetermined range.

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer of the conductive member comprises a matrix domain structure, at least a part of the domains Dt is exposed at the conductive member outer surface, the matrix has a volume resistivity R1 of larger than 1.00×10.sup.12 Ω.Math.cm, the domains Dt has a volume resistivity of smaller than R1, the developing device comprises the toner, domains Dc formed of the crystalline material exist in a cross section of the toner, distances between adjacent wall surfaces of the domains Dc is from 30 to 1,100 nm, and a weight-average particle diameter D4 of the toner and distances Dms between adjacent wall surfaces between the domains Dt satisfies D4≥Dms.

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, the conductive layer at the outer surface of the conductive member comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the outer surface of the conductive member, the matrix has a volume resistivity R1 of larger than 1.00×10.sup.12 Ω.Math.cm, the volume resistivity R1 of the matrix is 1.0×10.sup.5 times or more a volume resistivity R2 of the domains, the developing device comprises the toner comprising a toner particle and a silica fine particle, and a coverage ratio of the toner surface with the silica fine particles is from 62.0% by area to 100.0% by area as determined by X-ray photoelectron spectroscopy.

The process cartridge includes an electrophotographic photosensitive member having a first support and a photosensitive layer; and a charging member. In the photosensitive member when an electric current is measured which flows when a voltage is applied to a surface while being varied, a gradient a.sub.1 of a low electric field region and a gradient a.sub.2 of a high electric field region satisfy a.sub.2/a.sub.1≥1.50, in a graph. The charging member includes a second support having an electroconductive outer surface, and a second electroconductive layer including a matrix and a plurality of domains being dispersed in the matrix, at least a portion of the domain is exposed to an outer surface which includes at least the matrix and at least a portion of the domain, and a volume resistivity ρ.sub.M of the matrix is 1.00×10.sup.5 times or higher of a volume resistivity ρ.sub.D of the domain.

An image forming unit includes a photoreceptor and a charging member that comes into contact with a surface of the photoreceptor and charges the photoreceptor, in which the photoreceptor includes a conductive substrate, and a lamination type photosensitive layer disposed on the conductive substrate and including a charge generation layer and a charge transport layer, the charge transport layer contains at least one of a polyester resin that has a constitutional unit having an aromatic ring or a polycarbonate resin that has a constitutional unit having an aromatic ring, the charging member includes a support member and an elastic layer disposed on the support member, and the elastic layer has a storage elastic modulus G′ of 5.0 MPa or less at a frequency of 100 Hz in dynamic viscoelasticity measurement under a temperature condition of 24° C.

A roll member includes a conductive elastic layer, and a surface layer provided on the conductive elastic layer. The surface layer contains a crosslinked product of crosslinkable nylon, the crosslinking degree of the surface layer specified by formula (1) below is 0.3 or more and 0.7 or less, and the thermal degradation index of the surface layer specified by formula (2) below is 2.1 or more and 2.3 or less.

Crosslinking degree=absorbance at 1078 cm.sup.−1÷absorbance at 2935 cm.sup.−1  Formula (1):

Thermal degradation index=absorbance at 1638 cm.sup.−1÷absorbance at 1543 cm.sup.−1  Formula (2):

A charging roller comprising an electroconductive mandrel and an electroconductive layer as a surface layer, the electroconductive layer including a matrix containing a cross-linked product of a first rubber and domains dispersed in the matrix, each of the domains containing a cross-linked product of a second rubber and an electroconductive particle, the domains each having a volume resistivity lower than a volume resistivity of the matrix, and when sampling a cubic sample of the electroconductive layer having a side of 20.0 μm from a region from an outer surface of the electroconductive layer to a depth of 20.0 μm, 50 number % or more of all the domains in the cubic sample satisfy a specific condition.