PURPOSE: To improve the productivity of a braider by automatically exchanging an empty bobbin with a full bobbin by the cooperation of an exchange device with a supplier, when it is detected that the yarn of a bobbin loaded on a bobbin carrier is used up.

CONSTITUTION: In a braider for braiding fibers, bobbin carriers C are rotated and run along tracks grooved on an upper curved plate U, and many yarns Y are crossed with each other to form a braid (b) at a braiding point Z on a mandrel (m). When a detection means s1 comprising a projector and a light receptor detects that the yarn (y) of a bobbin loaded on the bobbin carrier C is used up, the braider B is stopped, and a supplier S moves forward to suction-hold the yarn connected to the braid (b) and cut the excessive part of the yarn. An exchange device N is subsequently operated to exchange the empty bobbin with a new full bobbin. The supplier S binds the yarn end of the full bobbin with the yarn (y) connected to the braid (b), and subsequently returned to a waiting position to again drive the braider B.