PURPOSE: To effectively perform shearing without any obstruction in a shearing machine for a lamellar material by applying machining force in a drirection of narrowing a gap between both blades, and thereby preventing a material to be cut from being rendered to beinding and byte.

CONSTITUTION: With a hydraulic pressure projecting cylinder being operated to permit a material to be cut to slide on a base and reach a position of a lower cutting blade 2, the hydrauric pressure is applied to a cutting cylinder to permit a upper cutting blade 1 to strike the material to be cut. Thereupon, a press cylinder is operated by an electric signal to cause a press board to be lwered for pressing down the material, while to cause a upper cutting board to be lowered for shearing the material. Then, the blade 1 is rendered to vertical shearing stress P from a cut edge. The stress P produces force P sin α along a slanted lower surface 5 of the upper cutting board 3a, whereby the board 3a is forced to slide diagonally to the upper part to provide force in a direction of narrowing a gap between both of the blades 1, 2. Thus, the material to be cut can be prevented from being rendered to bending and byte.