A draft apparatus (11) in a spinning machine is provided with a front bottom roller (12), a middle bottom roller (13), a back bottom roller (14), and motors (15, 16a, 16b, 17a, 17b) for independently driving the rollers (12, 13, 14). Lock means (21) inhibits the back bottom roller (14) from being rotated at least in a forward rotating direction, at least for a predetermined period after a spinning stop of the spinning machine. Accordingly, it is possible to inhibit a fiber from being excessively fed due to a torsional return of the bottom roller under the stop period of the machine, and it is possible to suppress yarn unevenness at a time of starting (Fig. 1).