To provide a wood crusher capable of being rapidly restored from an operation stop state when foreign matter or the like is bitten in the crusher to stop the operation of the crusher.

The wood crusher is equipped with a crushing rotor 10 for crushing wood of an object to be crushed, a crusher frame 17 for rotatably supporting the crushing rotor 10, a housing 13 equipped with a fixed blade 12 and rotatably provided to the crusher frame 17 so as to be positioned in the periphery of the crushing rotor 10, and a housing opening permitting means 14 provided to the revolving part of the housing 13 and the crusher frame 17 and permitting the revolution to the open direction of the housing 13 at the time of overload to the fixed blade 12. By this constitution, the bearing or the structure of the crushing rotor 10 can be prevented from being damaged by excessive load and it is unnecessary to replace a new part at the time of breaking of a shear pin and restoration can be easily and rapidly performed.