A shredder that shreds a recording medium which includes, on a surface thereof, an image forming portion and a holographic memory portion in which data is recorded. The shredder includes a data destroying unit that destroys at least the data recorded in the holographic memory portion and a shredding unit that shreds the entire recording medium. Thus, when a recording medium to which has been added a holographic memory portion in which useful information is recorded is to be discarded, the data(information) recorded in the holographic memory portion can be safely destroyed so that the data can no longer be read.