A torque measuring apparatus for detecting torque in a noncontacting state on the basis of the magnetostrictive amount of a rotary magnetic member for transmitting the torque which is detected by means of a magnetic sensor. The measuring apparatus comprises: a timing signal generator for dividing the rotational angle of the rotary magnetic member into a given number of segments and outputting a predetermined timing signal every time a rotational angle of the rotary magnetic member passes each segment; an offset signal generator for setting in advance for each segment an offset signal to be output from the magnetic sensor depending upon the rotational angle of the rotary magnetic member, and subsequently outputting an offset signal which corresponds to a respective segment on the basis of the timing signal; and a subtractor for subtracting the offset signal from the detection signal of the magnetic sensor at each segment, whereby the transmitted torque of the rotary magnetic member is measured on the basis of the output of the subtractor.