To efficiently reduce the volume of car shredder dust by compression.

The optimum charging quantity of the dust is determined according to the change of the physical properties of the dust charged in a compression chamber 5 by metering the dust carried into a hopper 3 by a metering means 4. The volume of the charged dust is reduced in the compression chamber 5 by a compression means 5, and the compressed/volume-reduced dust D4 is discharged by a discharging means 6 from a discharge tunnel 7 extending in the direction orthogonal to the compression chamber 5. A binding body 20 is stretched around the volume-reduced dust D4 in the direction parallel to an opening end of the discharge tunnel 7. The volume-reduced dust D4 discharged from the discharge tunnel 7 is received, and carried by a carrying means 22. The binding body 20 is stretched around the volume-reduced dust D4 in the direction across the binding direction of the first binding means 21.