An operating knob for an operating apparatus extends away from a reference plane that delimits the operating knob on a rear side. The operating knob is in the form of a three-dimensionally protruding body in relation to the reference plane up to a knob height. The operating knob has at least one side wall extending between the reference plane and the knob height at an angle greater than 20° with respect to the reference plane as a placement surface for at least one finger operating the operating knob. Luminous outputs of at least one luminous segment or a pixel matrix are provided on the side wall.