Process cartridge and electrophotographic apparatus

A process cartridge detachably attachable to an electrophotographic apparatus body, comprising:

• an electrophotographic photosensitive member comprising a support, a photosensitive layer and a protective layer in this order, the protective layer comprising a metal oxide particle;
• and
• a charging member comprising a support having an electroconductive outer surface, and an electroconductive layer provided on the outer surface of the support;
• the electroconductive layer having a matrix comprising a first rubber with a plurality of domains dispersed in the matrix, the domains comprising a second rubber and an electron electroconductive agent,
• at least some of the domains being exposed on an outer surface of the charging member, the outer surface of the charging member comprising the matrix and at least some of the domains, wherein
• Rcm is at least 1.0×105 times Rcd when Rcm is a volume resistivity of the matrix and Rcd is a volume resistivity of the domains, and
• 0.5<Sd/Sm<100 when Sm is a number average primary particle size of the metal oxide particle and Sd is an average value of equivalent circle diameters of the domains as observed from the outer surface of the charging member.