A developing roller is provided having a surface that has excellent effect of suppressing exudation of low molecular weight substances from an elastic body, excellent toner release properties, and sufficient flexibility in which cracks do not easily occur even by repeated image formation. The developing roller carries and conveys toner to develop electrostatic latent images on a photosensitive drum with the toner and includes in this order a mandrel, an elastic layer, and a surface layer. The surface layer includes a silicon oxide film containing carbon atoms chemically bonded to silicon atoms. The silicon oxide film has an abundance ratio of oxygen atoms forming chemical bonds with silicon atoms to silicon atoms (O/Si) of 0.65 or more and 1.95 or less, and an abundance ratio of carbon atoms forming chemical bonds with silicon atoms to silicon atoms (C/Si) of 0.05 or more and 1.65 or less.