To quickly and accurately change a preparatory plan of an automatic winder caused by a lot change so as to automatically change an initial position and an operation position of a fixed cylinder and a movable cylinder in response to a difference in a vertical dimension of a bobbin.

The fixed cylinder and the movable cylinder are individually elevated and lowered by first and second respective elevating and lowering mechanisms. The respective elevating and lowering mechanism are constituted of a guide member, a slider and a driving structure that elevates and lowers the slider. The driving structure is constituted by using a stepping motor as a driving source. An operation state of the stepping motor is controlled by a control circuit based on bobbin data input in advance to the control circuit and a position signal detected by a position detector of the stepping motor. Thus, the initial position and the operation position of the fixed cylinder and the movable cylinder can be automatically set in response to the difference in the vertical dimension of the bobbin.