A separation device includes a first shredding unit, a first separation unit, a second shredding unit, and a second separation unit. The first shredding unit shreds a processing target containing a first material and a second material. The first separation unit rotates a first tubular portion in a state in which the processing target shredded by the first shredding unit is accommodated therein, thereby separating the second material passing through first holes from the processing target. The second shredding unit shreds the processing target from which the second material passing through the first holes is separated by the first separation unit. The second separation unit rotates a second tubular portion in a state in which the processing target shredded by the second shredding unit is accommodated therein, thereby separating the second material passing through second holes from the processing target.