A document shredder is provided with a transport system that holds and transports paper, and a shredding system that shreds the paper while rotating at a circumferential speed higher than a transporting speed of the transport system, wherein, a part of elements constituting the transport system is in common with a part of elements constituting the shredding system and a point of action of the transport system is placed substantially at the same position as a point of action of the shredding system, with respect to a paper transporting direction, and alternatively, the shredding system is arranged successively from the transport system. Since this shredder is assembled in such a manner that a part of elements constituting the transport system to hold and transport the paper is in common with a part of elements constituting the shredding system, it is possible to be downsized. Furthermore, since the points of action are provided independently from the transport system, it is possible to enlarge the speed ratio between the paper transporting speed and the rotating speed of the shredding blade, whereby the paper entirely up to the end can be shredded with reliability, by only onetime passing of the paper.