To provide an excellently safe separation device enabling precise and efficient separation operation of yarns and providing excellent operability; and to provide a separation method.

The separation device has a separation roll having many yarn-guiding grooves extended in the circumferential direction, and a planet roll formed so as to be freely turned around the separation roll and so as to be freely moved between a separation position and a retreated position. Many yarns bundled by twisting are gradually separated on the planet roll while being pulled, and when the pitch of the separated yarns coincides with the pitch of the yarn-guiding grooves, the planet roll is retreated to put the many yarns in the yarn-guiding grooves at once.