To eliminate necessity for replacement of upper/lower tool rest total unit, so as to replace upper/lower tools in a short period and attain reduction of a cost required for replacement, by changing a structure of a mounting part of the upper/lower tools in a shearing type shredder.

This shearing type shredder 1 is provided with a cutter device 3 having an upper tool rest 13 mounting an upper tool 15 to be freely lifted and a lower tool rest 17 mounting a lower tool 19 to shear a waste into band shape by meshing the upper tool 15 with the lower tool 19, the shredder is constituted by mounting the upper tool 15 in the upper tool rest 13 through a mounting base 14 for the upper tool and mounting the lower tool 19 in the lower tool rest 17 through a mounting base 18 for the lower tool.