A process cartridge is disclosed which is detachably mounted on an apparatus for forming an image using toner, and which has a process cartridge housing. The process cartridge housing includes: a smoothed surface portion including an inner face and an outer face; at least one protruding portion formed on the smoothed surface portion so as to protrude therefrom; and a structure having a surface configured for physically facilitating removal of the toner from the process cartridge housing, once attached thereto.