PURPOSE: To prevent formation of burrs in shearing with a shearing machine by allowing the plate to be cut to sink at its final stage of shearing while it is pinched by a movable upper edge and the oversurface of conveyor.

CONSTITUTION: In this shearing machine 1 a back gauge 13 sinks together with a slide 9 holding a movable upper edge 11. This back gauge 13 takes horizontal position in close contact with the oversurface of a belt 23 so that a plate to be cut 25, which is fed from the front getting over the stationary lower edge 5, does not creep under the back gauge 13 when traveling backward on the oversurface of the ring-shaped belt 23 of a belt conveyor 21. Accordingly the back gauge 13 depresses the belt 23 when sink of the upper edge 11 commences, to ensure that shearing is performed free from generation of burrs.