To mechanically remove punching waste left in die cutting holes of corrugated boards by movably, detachably, and vertically providing piercing tools on an elevating frame.

Corrugated boards 32 are loaded on the top face of a mount bar 2 in such a state as being in contact with a left side gage 5 and a back gage 7. In this case, a plurality of corrugated boards 32 are bound by a string, etc. This constitution prevents the deviation of the corrugated boards 32 in working. Secondly, a changeover switch 25a is set to 'interlocking' and a foot switch 26 is pushed so that the corrugated boards 32 are positioned and fixed by the left/right side gages 5, 6 and the back gage 7 as positioning and fixing means, an elevating frame 3 is lowered, and the waste in die cutting holes 33 of the corrugated boards 32 is removed by piercing tools 4.