To heighten the detection precision of a noncontact type torque sensor for detecting the torque from the twisting of rotary shaft.

The torque sensor comprises the shaft 1 applied of twisting torque; the 1st and the 2nd rings 2 and 3 for relatively rotating accompanying the twisting of the shaft 1; the magnetic field variation means for varying the magnetic field between the 1st and 2nd rings 2 and 3, according to the relative rotational positions of the 1st and 2nd rings 2 and 3; and the 1st and 2nd coils 11 and 12 provided on the periphery of the 1st and the 2nd rings 2 and 3 opposite to each other. The 1st coil 11 is impressed with a signal oscillating at a constant frequency and a constant amplitude, and the 2nd coil 12 is detected its induced electromotive force, and the twisting torque, impressed on the shaft 1 corresponding to the induced voltage, is calculated.