Provided is a developing device including: a toner; and a developer carrying member. The developer carrying member includes an electroconductive substrate and a surface layer on the substrate, the surface layer being a single layer and including a matrix containing a crosslinked urethane resin as a binder, wherein E1 ≥200 MPa and 10 MPa≤E2 ≤100 MPa, where E1 is an elastic modulus of the matrix in a first region from an outer surface of the surface layer to a depth of 0.1 and E2 is an elastic modulus of the matrix in a second region from a depth of 1.0 to 1.1 μm from the outer surface. The toner includes a toner particle containing a binder resin and a colorant and having a Martens hardness of 85 to 1,100 MPa when measured under a condition of a maximum load of 2.0×10.sup.−4 N.

Provided is a developing device including: a toner; and a developer carrying member. The developer carrying member includes an electroconductive substrate and a surface layer on the substrate, the surface layer being a single layer and including a matrix containing a crosslinked urethane resin as a binder, wherein E1≥200 MPa and 10 MPa≤E2≤100 MPa, where E1 is an elastic modulus of the matrix in a first region from an outer surface of the surface layer to a depth of 0.1 and E2 is an elastic modulus of the matrix in a second region from a depth of 1.0 to 1.1 μm from the outer surface. The toner includes a toner particle containing a binder resin and a colorant and having a Martens hardness of 85 to 1,100 MPa when measured under a condition of a maximum load of 2.0×10.sup.−4 N.

Provided are a developing roll for an electrophotographic device and a method for manufacturing a developing roll for an electrophotographic device, with which toner fusion and toner filming are suppressed. A developing roll for an electrophotographic device includes a shaft body and an elastic body layer formed on an outer circumference of the shaft body. The surface of the elastic body layer has a plurality of large protruding parts having a width of 3.0 to 12 μm and a height of 3.0 to 12 μm, and the side surface of the large protruding part 16 has a plurality of small protruding parts which form convex-concavity having a ten-point average roughness Rz of 2.0 to 4.0 μm.

Provided are a developing roll for an electrophotographic device and a method for manufacturing a developing roll for an electrophotographic device, with which toner fusion and toner filming are suppressed. A developing roll for an electrophotographic device includes a shaft body and an elastic body layer formed on an outer circumference of the shaft body. The surface of the elastic body layer has a plurality of large protruding parts having a width of 3.0 to 12 μm and a height of 3.0 to 12 μm, and the side surface of the large protruding part 16 has a plurality of small protruding parts which form convex-concavity having a ten-point average roughness Rz of 2.0 to 4.0 μm.

A conductive roller includes a supporting member and a conductive elastic foam layer disposed on the supporting member. In a spectrum of amplitude (m) vs. period (m) obtained by subjecting a roughness waveform of the outer circumferential surface of the conductive elastic foam layer in an axial direction to fast Fourier transformation, the integrated value St of the amplitude within a period range of 100 m or more and 300 m or less is 455 m or less.

Provided is a developing roller comprising an electroconductive substrate and an electroconductive layer thereon, the electroconductive layer retaining resin particles so that at least a part of each of the resin particles is exposed on an outer surface of the developing roller; the outer surface of the developing roller constituted by electrically insulating domains and an electroconductive matrix, assuming that a square region 200-m in a side is put on the outer surface of the developing roller, the square region including the domains, among the domains in the square region at least two of them satisfying specific condition, and assuming that the outer surface of the developing roller is charged, and creating a potential map of the charged outer surface of the developing member, the two domains satisfying the specific condition being ascertained in the potential map.

Provided is a developing roller comprising an electroconductive substrate and an electroconductive layer thereon, the electroconductive layer retaining resin particles so that at least a part of each of the resin particles is exposed on an outer surface of the developing roller; the outer surface of the developing roller constituted by electrically insulating domains and an electroconductive matrix, assuming that a square region 200-m in a side is put on the outer surface of the developing roller, the square region including the domains, among the domains in the square region at least two of them satisfying specific condition, and assuming that the outer surface of the developing roller is charged, and creating a potential map of the charged outer surface of the developing member, the two domains satisfying the specific condition being ascertained in the potential map.

Provided is an electrophotographic member including: an electroconductive substrate; and an elastic layer on the substrate, the elastic layer constituted by a single layer, the elastic layer containing a silicone rubber having a dimethylsiloxane structure, wherein when a peak top temperature of an ion thermogram derived from the dimethylsiloxane structure, the ion thermogram being measured from a first sample sampled from a first region having a thickness of 0.5 m from a first surface of the elastic layer toward a second surface thereof, is represented by T1, and a peak top temperature of an ion thermogram derived from the dimethylsiloxane structure, the ion thermogram being measured from a second sample sampled from a second region corresponding to a thickness of 1.0 m to 1.5 m from the second surface toward the first surface, is represented by T2, T1 and T2 satisfy a relationship of T1>T2.

A developing device includes a cylindrical developing roller, a regulation member, a magnetic member, and a synthetic resin member. The regulation member includes a first opposing surface facing an outer circumferential surface of the developing roller. The magnetic member is arranged on a side surface of the regulation member. The synthetic resin member is arranged on a side surface of the magnetic member. The synthetic member includes a second opposing surface facing the outer circumferential surface of the developing roller. The second opposing surface is tilted at 40 or more but 60 or less with respect to the first opposing surface to be increasingly distant from the outer circumferential surface of the developing roller toward an upstream side in a rotating direction of the developing roller. A solubility parameter of a material of the synthetic resin member is 23 (J/cm.sup.3).sup.1/2 or more. Magnetic toner contains toner and resin fine particles.