To solve the following problems: when slate and concrete waste is discarded or recycled, they are usually frequently crushed by a crusher, which is usually provided with a rotating and driving crushing tool in the body, receives introduction of material to be crushed from above and discharges the crushed material from the bottom, and in such a crusher, only the tip end portion of the crushing tool is frequently damaged but the whole crushing tool should be exchanged although other portions are not damaged, and for preventing the exchange, there is a crusher which enables the exchange of the tip end portion but the crusher increases its cost.

A crusher crushes a material to be crushed between rotating crushing rollers and includes at least a pair of counter-rotating crushing rollers different in the number of revolutions.