To provide a method for manufacturing a special yarn having a short slub dispensing with an electromagnetic clutch or a motor having a large volume for rapidly increasing and decreasing the speed of a front roller in order to create the short slub and hardly reducing productivity.

A spinning machine having a draft part in which a front roller and a back roller are driven by separate variable speed motors is used, the speeds of the front roller and the back roller are temporary decreased before operating the creation of the slub without changing the thickness of the yarn, and the spinning speed is decreased slower than that at the normal spinning. In such a state, the creation of the slub is operated.