The torque detecting apparatus comprises an input shaft to which a torque is inputted, an output shaft for outputting the inputted torque, a connecting shaft for connecting the input shaft and the output shaft to transmit the torque, a coil for detecting a torque applied from the input shaft to the connecting shaft based on a torsional angle which arises at the connecting shaft, and a holding cylinder for holding the coil coaxially, wherein the holding cylinder has inside thereof a recess extending in the circumferential direction, and the coil is fitted in the recess. Projections for supporting the holding cylinder at a predetermined position are provided on the outer surface of an axial portion which does not have the recess. Accurate torque detection can be effected even when pressure applied to the projections provided at the holding cylinder constituting the torque detecting apparatus is changed.