To provide an apparatus for continuously and densely compressing shredded paper pieces and a document crusher having the same, which can be installed in a small space.

An apparatus for compressing paper pieces contained in a container bag B while an opening of the container bag B containing the shredded paper pieces 1 is being held opened is provided with a holding body 39 for holding the opening of the container bag B in an opened state and a pressurizing device 31 provided above and in a vicinity of the opening of the bag for transferring the paper pieces into the opening and forcing the same into the interior of the bag. The pressurizing device 31 comprises a pair of rotary members 34 having traveling parts in pressure contact with each other.