PURPOSE: To prevent an empty can crusher from being damaged or out of order when a hard foreign matter that can not be crushed with a crush roller is bitten in.

CONSTITUTION: The shaft 5 of an angular toothed driving crush roller that is rotated by a motor 8 is axially supported to a frame; the shaft 7 of a trailing crush roller is axially supported by the bearing 10 that is freely slidably supported by a guide block 11; the bearing 10 is directly connected to the piston rod 14 of a hydraulic cylinder 13; the bearing 10 that is pressurized with the hydraulic cylinder 13 is abutted on a stopper bolt 16; the angular teeth of a pair of crush rollers are made to engage each other at a prescribed space; a sensor 17 by which the retreat of the bearing 10 is detected is provided; the motor 8 is made ready for inching and reversing by means of the detecting command from the sensor 17 and thereby empty cans are crushed.