To provide a shearing device and a shearing method repeatingly manufacturing steel sheet materials excellent in parallelism of a pair of shear end surfaces by a simple mechanical constitution.

The shearing device 1 repeatingly manufactures steel sheet materials 8 of a predetermined length by shearing while feeding a long belt-like steel sheet 80 by a predetermined amount. The shearing device 1 is so configured that pilot pins 5 are insertingly arranged in a plurality of reference holes 83A formed in a downstream side raw material portion 81, a plurality of next reference holes are formed in an upstream side adjacent portion 82 by a plurality of perforating punches 4 in a state the downstream side raw material portion 81 is held by a downstream side punch 21 and a downstream side dice 22 and the upstream side adjacent portion 82 is held by an upstream side punch 31 and an upstream side dice 32, and the downstream side punch 21 and the downstream side dice 22, and the upstream side punch 31 and the upstream side dice 32 are moved relatively to each other while maintaining the state the plurality of next reference holes have been formed.