PROBLEM TO BE SOLVED: To solve a problem that a cable, a flexible pipe or the like cannot pass inside a rotating shaft, since a space area passing inside the rotating shaft cannot be secured. SOLUTION: A rotating device comprises a communication unit, having a transmission part including a coil 47; a magnetic body 46 covering the coil 47 and a conductive line with an insulating film 53 connected to the coil 47; and a receiving part which includes a coil 45; a magnetic body 44 covering the coil 45 and a conductive line with an insulating film 52 connected to the coil 45; and a bearing 41, connecting a hollow fixed member 40 and a hollow rotating member 42, and being rotatable with respect to the hollow fixed member 40, wherein the coil 47 and the coil 45 are formed so as to wind about the rotating axis S1 of the bearing 41; the magnetic body 46 and the magnetic body 44 face each other, with a gap G formed in a rotating axis S1 direction; and the communication unit is provided in the inside of the fixed member 40 and the rotating member 42. COPYRIGHT: (C)2010,JPO&INPIT