An image forming apparatus for forming an image with a developing agent, includes: a collecting-developing-agent occurring part in which the collecting developing agent to be collected in the developing agent occurs; a collection container for accommodating the collecting developing agent; a transporting part provided so as to connect the collection container and the collecting-developing-agent occurring part and for collecting and transporting the collecting developing agent occurring in the collecting-developing-agent occurring part; and a replacement part removably mounted in an apparatus body, wherein the collection container is mounted to be integrated with the replacement part.