Cleaning roller, charging device, image forming apparatus, and method of manufacturing cleaning roller

The invention provides a cleaning roller in which inconvenience due to rotation fluctuation of the cleaning roller may be effectively eliminated and downsizing of the apparatus may be realized, a charging device, an image forming apparatus including the charging device, and a method of manufacturing a cleaning roller. A plurality of uneven portions extending so as to twist in a circumferential direction of the cleaning roller are formed on the surface of the cleaning roller. A rotation shaft of the cleaning roller is inserted into a cylindrical hole of a cylindrical cleaning member in which the plurality of uneven portions are formed along an axial direction, and the clean member and the rotation shaft are fixed in a state where the cleaning member is twisted in a circumferential direction. The cleaning member, in which the plurality of uneven portions extending so as to twist in the circumferential direction are formed, is molded by rotating an extrusion molding die while extruding anextrusion molding materi