To provide a shredder device which solves the problem that a conventional shredder device with a short distance from an opening of a sheet inserting opening to the cutting blade makes a baby's slender finger, etc. enter into the inner part of the sheet inserting opening and therefore cause the tip of a finger to inevitably contact a cutting blade to be cut off in error.

A finger entrainment prevention device is installed to the shredder device having the sheet inserting opening for inserting a sheet to be shred, wherein this device has a cover body having a penetration hole with a sheet insertable space and a contact side contacting the shredder device, and an installation means for detachably installing the finger entrainment prevention device on the shredder device in the contact side of the cover body so that the penetration hole communicates with the sheet inserting opening.