Patent ID: 8503916

Claim:
A developing roller for carrying and transporting toner and developing an electrostatic latent image on a photosensitive drum with the toner, comprising a mandrel, an elastic layer and a surface layer in this order, wherein the surface layer comprises a silicon oxide film containing at least a carbon atom chemically bonded to a silicon atom, an oxygen atom chemically bonded to a silicon atom, and a fluorine atom chemically bonded to a silicon atom and/or a carbon atom, and wherein the silicon oxide film has an abundance ratio of the fluorine atom to the silicon atom (F/Si) of 0.10 or more and 0.50 or less, an abundance ratio of the oxygen atom forming a chemical bond to the silicon atom to the silicon atom (O/Si) of 0.50 or more and 1.50 or less, and an abundance ratio of the carbon atom forming a chemical bond to the silicon atom to the silicon atom (C/Si) of 0.30 or more and 1.50 or less.