PURPOSE: To provide a torque sensor in which the fluctuation of zero point due to the rotational angle under no-load is detected and the data thereof is stored and the measurement is corrected at the time of torque measurement by reading out the data thus stored.

CONSTITUTION: A signal is delivered on an external control signal line 36 to a measurement operating circuit 28 thus bringing the circuit into a detection/memory mode. The circuit 28 confirms the no-load state of a detection shaft 10 and stores the torque measurement corresponding to the rotational angle of the shaft 10 for the first revolution of the shaft 10. For the second revolution, a measurement is read out from the memory 32 and compared with the actual measurement value at each rotational angle. If they are substantially equal to each other, a detection/memory completion signal is placed on a signal line 38. Consequently, the signal on the line 36 is turned OFF and a switching is made to torque measurement mode. In this regard, zero point fluctuation data for each angle is fed from the memory 32 to the circuit 28 along with the rotational angle of the shaft 10 detected by a rotational angle detector 30 and the torque measurement. The error is subtracted from the torque measurement to produce a correct torque value which is then placed on a torque signal line 34.