An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer and contains a charge generating material, a hole transport material, an electron transport material, and a polyarylate resin. The polyarylate resin includes repeating units represented by formulas (1), (2), and (3).

##STR00001##

A ratio n.sub.1/n.sub.2 of the number n.sub.1 of repeats of the repeating unit represented by formula (1) to the number n.sub.2 of repeats of the repeating unit represented by formula (2) is at least 1.0.

An electrophotographic 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, in which the charge transport layer contains a polyester resin having a structure represented by Formula (1) at a terminal and a charge transport material, and in a case where a weight-average molecular weight Mw of the polyester resin is defined as A (×10,000), a value of a ratio M1/M2 of a mass M1 of the charge transport material to a mass M2 of an entire charge transport layer is defined as Cs, and an average thickness of the charge transport layer is defined as Ds (μm), expressions of 7≤A≤40, 0.28≤Cs≤0.55, 27≤Ds≤50, and 5.0≤(A×Ds)/(Cs×100)≤70 are satisfied,

##STR00001## in Formula (1), nd represents an integer of 0 or greater and 4 or less, nd number of Rd's each independently represent a hydrocarbon group having 1 or more and 4 or less carbon atoms, L represents an ether bond or a —O—C(═O)— group, and * represent a bonding portion.

An electrophotographic photoreceptor includes a conductive substrate, an undercoat layer disposed on the conductive substrate, and a lamination type photosensitive layer disposed on the undercoat layer and including a charge generation layer and a charge transport layer, in which the charge transport layer contains a charge transport material and a polyester resin, and in a case where an average thickness of the charge transport layer is defined as As (μm) and an average thickness of the undercoat layer is defined as Bs (μm), expressions 27≤As≤50, 10≤Bs≤40, and 0.70≤As/Bs≤4.80 are satisfied.

An image forming apparatus includes an image bearing member, a charger, a light exposure device, a development device, a transfer belt, a primary transfer device, a secondary transfer device, and a cleaning member. The cleaning member is pressed against a circumferential surface of the image bearing member and collects residual toner remaining on the circumferential surface of the image bearing member as a result of primary transfer of a toner. The transfer belt has a surface resistivity of at least 6 Log Ω and no greater than 11 Log Ω. A linear pressure of the cleaning member on the circumferential surface of the image bearing member is at least 10 N/m and no greater than 40 N/m. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer. The image bearing member satisfies formula (1): $\begin{array}{cc}0.06\leqq \frac{V}{\left(Q/S\right)\times \left(d/{\epsilon }_r.Math.{\epsilon }_0\right)}.& \left(1\right)\end{array}$

An electrophotographic photoconductor includes: a conductive substrate; and a single-layer-type photoconductive layer that is provided on the conductive substrate and contains a binder resin, a charge generating material, a hole transporting material, and an electron transporting material, in which a volume resistivity of the photoconductive layer after wear is 5.0×10.sup.10 Ω.Math.cm or more and 2.0×10.sup.11 Ω.Math.cm or less when a ratio of a thickness of the photoconductive layer after wear to a thickness of the photoconductive layer before wear (the thickness of the photoconductive layer after wear/the thickness of the photoconductive layer before wear) is 0.8.

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer on the conductive substrate. The electrophotographic photoreceptor has an outermost surface layer that contains fluorine-containing resin particles and an antioxidant. The fluorine-containing resin particles contain 0 or more and 30 or less carboxy groups per 10.sup.6 carbon atoms. A decrease in weight of the antioxidant when heated at 150° C. for 10 minutes in an air atmosphere is 40 mass % or less.

An image forming apparatus includes an image bearing member, a charger, a light exposure device, and a development device. The charger charges a circumferential surface of the image bearing member to a positive polarity. The light exposure device exposes the charged circumferential surface of the image bearing member to light to form an electrostatic latent image on the circumferential surface of the image bearing member. The development device supplies a toner to the electrostatic latent image through application of a developing bias. The developing bias is a voltage of an alternating current voltage superimposed on a direct current voltage. The alternating current voltage has a frequency of 4 kHz or higher and 10 kHz or lower. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer. The image bearing member satisfies formula (1)

[00001]$\begin{array}{cc}0.60\leqq \frac{V}{\left(Q/S\right)\times \left(d/{\mathrm{.Math.}}_r.Math.{\mathrm{.Math.}}_0\right)}& \left(1\right)\end{array}$

A compound is represented by general formula (1). In general formula (1), R.sup.1 and R.sup.2 each represent, independently of one another, a hydrogen atom, a methyl group, or an ethyl group, and a sum of the number of carbon atoms of the chemical group represented by R.sup.1 and the number of carbon atoms of the chemical group represented by R.sup.2 is 2. R.sup.3 and R.sup.4 each represent, independently of one another, a hydrogen atom, a methyl group, or an ethyl group, and a sum of the number of carbon atoms of the chemical group represented by R.sup.3 and the number of carbon atoms of the chemical group represented by R.sup.1 is 2. A photosensitive layer of an electrophotographic photosensitive member contains at least a charge generating material, a hole transport material, and a binder resin. The hole transport material includes a compound represented by general formula (1) ##STR00001##

An electrophotographic photoconductor includes a conductive substrate; and a photosensitive layer provided on the conductive substrate and containing a charge generation material, a hole transport material, a first electron transport material, from 3% by mass to 40% by mass of a second electron transport material, a resin binder, and an inorganic oxide filler surface-treated with a silane coupling agent. In a dipole-dipole force component (a Hansen solubility parameter), the first electron transport material and the silane coupling agent have a difference of ΔSPa<2.50; the second electron transport material and the silane coupling agent have a difference of ΔSPb<2.50; and the first electron transport material and the second electron transport material have a difference of 0.30<ΔSPc<1.00. In a London dispersion force component (a Hansen solubility parameter), the resin binder and the silane coupling agent have a difference of ΔSPd<2.00.

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer on the conductive substrate. The electrophotographic photoreceptor has an outermost surface layer that contains fluorine-containing resin particles and an antioxidant. The fluorine-containing resin particles contain 0 or more and 30 or less carboxy groups per 10.sup.6 carbon atoms. A decrease in weight of the antioxidant when heated at 150° C. for 10 minutes in an air atmosphere is 40 mass % or less.