The present invention can provide a developing roller which can form a stable image in wide ranging environments from a low temperature/low humidity environment to a high temperature/high humidity environment. The developing roller includes a surface layer including 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. The silicon oxide film has an abundance ratio of the fluorine atom to the silicon atom (F/Si), an abundance ratio of the oxygen atom forming a chemical bond to the silicon atom to the silicon atom (O/Si), and an abundance ratio of the carbon atom forming a chemical bond to the silicon atom to the silicon atom (C/Si) have values in particular ranges, respectively.