The invention relates to a file shredder with a device for detecting metallic objects introduced into the paper feed of the file shredder, a cutting unit with rotating cutting tools, a motor for driving the cutting tools and a transmission device for connecting the motor to the rotating cutting tools. According to the invention, substantially all of the metallic components of the cutting unit of the file shredder surrounding the rotating cutting tools, the motor and the transmission device are connected with one another in an electrically conducting manner such that they lie on a common defined electric potential.