A fixation device set S includes an external fixation device which is attached on one end-side of first and second pins; and a pin fixture which is attached on the other end-side. The external fixation device includes a first and a second permanent magnets disposed with their same poles opposed to each other; a first holding portion provided in the first permanent magnet; a second holding portion provided in the second permanent magnet; first limiter portions sandwiching the first and the second permanent magnets from a second direction; and second limiter portions connecting the first limiter portions to each other. The first pins are inserted through through-holes in the first holding portion, whereas the second holding portion is attached to the second pin via a ball joint.