A separation device for separating unneeded matter from an extraction subject, the separation device being provided with: a formation unit forming a separation chamber through which the extraction subject passes； and a suction unit communicating with the separation chamber in a direction intersecting the direction in which the extraction subject passes, the suction unit suctioning air that is in the separation chamber. The formation unit has an input port for the extraction subject, the input port communicating with the separation chamber, and a discharge port for the extraction subject, the discharge port communicating with the separation chamber. The suctioning performed by the suction unit suctions air from the discharge port to the separation chamber.
