Electrophotographic apparatus, process cartridge, and cartridge set

An electrophotographic apparatus having an electrophotographic photosensitive member, a charging unit, and a developing unit for forming a toner image on a surface of the electrophotographic photosensitive member, wherein the charging unit has a conductive member disposed to be contactable with the electrophotographic photosensitive member; a conductive layer at the surface of the conductive member has a matrix and a plurality of domains dispersed in the matrix; at least a portion of the domains is exposed at the outer surface of the conductive member; the outer surface of the conductive member is constituted of at least the matrix and the domains; a volume resistivity R1 of the matrix is greater than 1.00×1012 Ω·cm; a volume resistivity R2 of the domains is smaller than R1; the developing unit contains the toner; and a dielectric loss tangent of the toner is at least 0.0027.