To provide a magnetostriction type torque sensor provided with stable characteristic without unevenness in magnetic resistance in the circumferential direction of a yoke and without any fluctuation of a zero point.

A rotary shaft 1 provided with a magnetic anisotropic part 2 on at least the surface, excitation and detection coils of a single layer 3, 4 or an excitation coil 3 and a detection coil 4 of a plurality of layers concentrically circularly wound in the neighborhood of the rotary shaft 1, a lead wire 6 led out from the excitation coil 3 and the detection coil 4, and a doughnut-like yoke 5 surrounding excitation coil 3 and the detection coil 4 and constituted of a circumferential plate face part 51 and a side plate part 52 provided on both side faces thereof are equipped. The yoke 5 provides a slit 54 having constant width making a round in the circumferential direction in the circumferential plate face part 51 or the side plate face part 52. The lead wire 6 is drawn out from the slit 54 to the outside.