To orderly and smoothly transmit power without generating dust, not to mention noise, by transmitting power from a drive shaft to a driven shaft through magnetic cylinders without contact.

In a conveying device (a roller conveyor) by magnetic power transmission, magnetic cylinder 20a, 20b, 20c, 20d and 20e are fixed at the specified distance to a drive shaft 19 connected to a shaft of a motor 18, magnetic cylinders 21a, 21b, 21c, 21d and 21e having the same structure are perpendicularly installed over the magnetic cylinders 20a, 20b, 20c, 20d and 20e, the ends of driven shafts 22a, 22b, 22c, 22d and 22e are connected to the magnetic cylinders 21a, 21b, 21c, 21d and 21e, the other ends are rotatably supported, and each two bearing discs 23a, 23b, 23c, 23d and 23e are fixed to intermediate parts of respective driven shafts at a specified distance. In the magnetic cylinders 20a to 20e and 21a to 21e, magnetic streaks are provided on the outer peripheral wall of the cylinders made of ferromagnetic metal at angles in relation to the center axis by alternately arranging N and S.