To prevent the formation of filling bar defect caused by the disturbance of the continuity of a weft density in the restart of a loom stopped by defective weft insertion.

A defective yarn is picked and removed and the loom is reversely rotated to a prescribed restarting position and restarted from the restarting position. In the above process, the opening is carried out according to a modified pattern SKsj (j=1, 2...) in place of the normal opening pattern Ski. The excessive warp tension and the generation of discontinuous weft density caused by unintentional movement of a normal yarn can be prevented by selecting the opening W of the modified pattern SKsj to satisfy the formula W=Ws<Wm wherein Wm is the maximum opening of the normal opening pattern Skij.