To promote labor saving and a higher efficiency by mechanizing a rotating operation for a threaded joint coupling for threaded reinforcing bars together.

An opening 68 capable of fitting a threaded joint 71 is drilled at the tip end surface of a gear box 57 of a continuous rotating equipment 51. Also, a pair of right and left rollers 64 are housed in a gear box 57; and if a motor 53 is driven while pressing the right and left rollers 64 against an octagonal nut portion 72 of the threaded joint 71, then the right and left rollers 64 are rotated at the same speed in the same direction through a gear mechanism in the gear box 57 thereby continuously rotating the threaded joint 71.