PURPOSE: To shear even the grid member fitted portion of a bundle material to be sheared very easily to a desired length by providing a breaking edge partially breaking the bundle material to be sheared in front of a shearing edge.

CONSTITUTION: A bundle material supporting mechanism 5 constituted of a receiving edge bed 1 having a receiving edge 2 and a bundle suppressor 3 holding a bundle material to be sheared C arranged on the receiving edge 2 is provided. A shearing mechanism 10 constituted with a cutting edge bed 11, a shearing edge 12 fixed to the cutting edge bed 11, and a breaking edge 13 fixed in front of the shearing edge 12 and reciprocated against the bundle material to be sheared C on the receiving edge 2 is provided. The bundle material to be sheared C is held by the bundle material supporting mechanism 5 by moving the bundle material to be sheared C in the arrow direction (a) to protrude it by a cut length and pushing the bundle suppressor 3 in the arrow direction (b). When the cutting edge bed 11 is moved in the arrow direction (c), the bundle material is partially broken easily, and all the remaining portion is sheared by the shearing edge 12.