A collection container is divided by a divider plate into waste developer collection chambers in communication with waste developer reception ports for each color developer and a single waste toner collection chamber in communication with waste toner reception ports for each color toner. Further, the divider plate is a part of the inner wall of the collection container and the part is installed extending in the vertical direction to define a clearance between the divider plate and the bottom plate of the collection container. This makes it possible to collect color waste toner and color waste developer with a simple configuration.