A device for reducing the size of biological tissue according to an embodiment includes a plate, and a thru-hole which penetrates the front and the rear of the plate and is defined by a plurality of edges of the plate, wherein each of the plurality of edges includes a protruding part protruding toward a center part of the thru-hole, and biological tissue may be reduced in size by being scratched and torn by the protruding parts while passing through the thru-hole.