Abstract: An assembly for attaching a coin separator to a coin stacker, wherein the coin stacker has a plurality of coin storage boxes for storing coins therein, and the coin separator assorts the plurality of sorts of coins supplied from outside and then delivers the assorted coins to the corresponding coin storage boxes. The assembly capable of attaching the coin separator to the coin stacker with ease comprises a main frame which is fixed to the coin stacker; a subframe which is movably coupled to the main frame, which holds the coin separator so as to be detachable, and which guides the coin separator between an engagement position where the coin separator and part of the coin stacker are held in engagement and a non-engagement position where they are not held in engagement; and a fixing member which fixes the coin separator and the subframe to the main frame at the engagement position.