To remarkably reduce vibration accompanied by the elevation of an upper blade holder, and let neither failure nor double cutting phenomenon accompanied by vibration occur at all.

This turn shear is so constituted that an upper blade holder 25 and a lower blade holder 22 are mounted so as to be freely rocked around a vertical shaft while a condition that the upper blade 26 can be meshed with the lower blade 25, is maintained. In this case, the upper blade holder 25 is mounted to a slide 12 so as to be freely rocked around the vertical shaft with respect to the slide 12, so that the upper holder is moved up and down together with the slide 12.