A container holding device includes a container guide member (60) that
holds a toner container (50). The toner container (50) can be detachably
attached to the container guide member (60). The toner container (50)
includes a soft, shrinkable bag (51) for storing contents such as toner.
The container guide member (60) can move between a first position at
which the toner container (50) is detachably attached and a second
position at which the contents of the toner container (50) can be
discharged. A moving unit moves the container guide member (60) between
the first and second positions. An external pressurizing unit shrinks the
bag (51) by applying external pressure, and applies a lower pressure when
the container guide member (60) is at the first position than at the
second position.