Abstract: A screen exchange device for reducing the size of a biological tissue according to one embodiment comprises: a disk comprising a plurality of screens each having at least one through-hole configured to reduce the size of a biological tissue, the screens having different through-hole characteristics; a first cover which covers a first side of the disk and includes a first opening through which a biological tissue passes; a second cover which covers a second side of the disk and includes a second opening through which the biological tissue passes; a housing configured to receive the disk; and a manipulator which selects any one screen among the plurality of screens and manipulates the first cover or the second cover such that the selected screen communicates with the first opening and the second opening.