A developing roller includes an electro-conductive shaft core and an elastic layer provided on an outer peripheral surface of the electro-conductive shaft core. The elastic layer includes a base layer formed of a rubber composition and an outermost layer formed on a surface of the base layer. The outermost layer is formed of a resin and is an incomplete film including a plurality of through-holes. A ratio of portions other than the through-holes of the outermost layer is 25% to 45% with respect to a total surface area of the elastic layer.