In a center-rotation type tailstock, unavailable time due to replacement of parts such as bearings is shortened. A built-in hole is formed in a tailstock spindle. A center rotating mechanism unit is attachable to and detachable from the built-in hole. In the unit, a rotary shaft is supported in a tubular body by bearings. The rotary shaft is made enable a center to be attached. When replacing the parts in the unit attached to the built-in hole, the unit is detached from the built-in hole, and another center rotating mechanism unit incorporating new parts is attached to the built-in hole.

In a center-rotation type tailstock, unavailable time due to replacement of parts such as bearings is shortened. A built-in hole is formed in a tailstock spindle. A center rotating mechanism unit is attachable to and detachable from the built-in hole. In the unit, a rotary shaft is supported in a tubular body by bearings. The rotary shaft is made enable a center to be attached. When replacing the parts in the unit attached to the built-in hole, the unit is detached from the built-in hole, and another center rotating mechanism unit incorporating new parts is attached to the built-in hole.