A bobbin processing device (103) is a device that supplies a yarn supplying bobbin to a yarn winding device (102). The bobbin processing device (103) includes suction systems (e.g., first suction system (51) and second suction system (53)), a blower for bobbin processing device (45), a suction duct for bobbin processing device (47), a first shutter device (52), and the like. The suction system processes a yarn of the yarn supplying bobbin by sucking air. The blower for bobbin processing device (45) generates a suction airflow. The suction duct for bobbin processing device (47) is arranged between the blower for bobbin processing device (45) and the suction systems. The first shutter device (52) switches conduction of the air of the suction duct for bobbin processing device (47).