Process cartridge and electrophotographic apparatus

An electrophotographic apparatus comprising:

• an electrophotographic photosensitive member to carry a toner image;
• charging means to electrically charge the electrophotographic photosensitive member;
• exposing means to form an electrostatic latent image on the electrophotographic photosensitive member charged with the charging means;
• developing means to develop with a toner the electrostatic latent image formed with the exposing means on the electrophotographic photosensitive member to form a toner image on the electrophotographic photosensitive member;
• an intermediate transfer belt having a contact part with the electrophotographic photosensitive member to perform, after primary transfer of the toner image from the electrophotographic photosensitive member to the intermediate transfer belt, secondary transfer of the primarily transferred toner image to a transfer material;
• and
• primary transfer means to primarily transfer the toner image from the electrophotographic photosensitive member to the intermediate transfer belt at the contact part;
• and
• comprising a process cartridge integrally supporting at least the electrophotographic photosensitive member, the intermediate transfer belt, and the primary transfer means and being detachably mountable to a main body of the electrophotographic apparatus,
• wherein after the contact part is formed by the electrophotographic photosensitive member and the intermediate transfer belt being brought into contact with each other under a linear pressure of 0.5 N/cm and left to stand for 10 hours in an environment of 45° C./95% RH, differences in the dark portion potential and the light portion potential of the electrophotographic photosensitive member between the contact part and the portion being not the contact part of the electrophotographic photosensitive member are respectively less than 20%, and no crack having a length of not less than 1 μm occurs in any of the surface of the electrophotographic photosensitive member and the surface of the intermediate transfer belt.