To provide a crusher, which cracks a waste material such as concrete or asphalt and peels and crushes a road bed even in a standard back hoe having no spare hydraulic pipe for an attachment attached to an arm of the back hoe.

The crusher 1 is constituted into substantially a clothepin shape, and includes a lower fixed jaw 2 fixed to an arm 5, and an upper movable jaw 3 in which a bucket hydraulic cylinder 4 of a back hoe is pivotally supported at an end opposite to a jaw portion thereof. The movable jaw is rotated by extension/contraction of the hydraulic cylinder, whereby a material to be crushed which is held between the movable jaw and the fixed jaw, is crushed and cracked. The distance between a crushing pivot point and a shaft support point of the bucket cylinder is set longer by about 2 to 6 times than the distance between the crushing pivot point and the jaw tip of the movable jaw. Thus, the material to be crushed can be crushed with an increased crushing force by the principle of leverage.