To provide a yarn twister capable of changing the twisting direction of the yarn in yarn-twisting devices.

This yarn twister 1 has a yarn-twisting devices each equipped with a spindle, a rotor rotating integrally with the spindle and a spindle-driving motor 32 for rotationally driving the spindle, and a changeover switch 57 for changing over the twisting direction of the yarn on the yarn-twisting device, and is so constituted as capable of setting the yarn twisting directions of the yarns in a part of a plurality of yarn-twisting devices in reverse direction to the twisting direction of the yarns on the residual yarn-twisting devices.