CONTAINMENT DEVICE, AND IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To provide a containment device or the like that can contain sheets while being made to fall in a relatively narrow area, even if there are a plurality of auxiliary containers capable of secondarily supporting a portion of sheets contained while being stacked on a loading surface in a partial area of the loading surface.SOLUTION: A containment device includes: a containing body having a loading surface for containing the sheets discharged from a sheet discharge port while being dropped and stacked; and a plurality of containing auxiliary bodies turnably attached at each position spaced apart in a direction of discharging the sheets, respectively, by using an axis with one end extending in a direction substantially perpendicular to a discharge direction as a supporting point, in a partial area of the loading surface of the containing body, and held by switching between a risen state and a fallen state with respect to the loading surface by the turning and also capable of secondarily supporting a portion of the sheets contained on the loading surface. The plurality of containing auxiliary bodies are configured such that at least the containing auxiliary bodies adjacent to each other are held while being overlapped in at least a portion thereof in the direction of discharging the sheets when being brought into the fallen state.