The reaction type crusher crushes the material by high-speed impact. When the material enters the hammer action area from the feed hole, it is impacted by the hammer under high speed and becomes crushed preliminarily. The strong impact force thrusts the material onto the reaction plate and shatters it for the second time. The material then springs back from the reaction plate and falls in the hammer area to repeat the process until it is shattered to a size below the discharge outlet and then is discharged by gravity.