PURPOSE: To reduce the space and to improve detecting effect, by inserting a detector comprising exciting coils and detecting coils into a hole, which is formed in the longitudinal direction of a bearing, and detecting torque at a plane, which is perpendicular to the longitudinal direction of a rotary shaft that is supported by the bearing.

CONSTITUTION: A torque detector 13 is inserted into a through hole 12, which is formed in the longitudinal direction of a bearing cap 4. Ring shaped amorphous thin films 10 and 11 are bonded to large-diameter parts 8 and 9. AC is conducted through exciting coils 16 and 17 of the torque detector, and steady state magnetic flux distribution is imparted between the exciting coils 16 and 17 and the amorphous thin films 10 and 11. When torque is applied to a crank shaft 1, permeability is changed due to magnetostriction effect, and electromotive force corresponding to the magnitude of the torque is generated in a pair of exciting coils 18 and 19. The electromotive force is read by a detector 21 and the torque is detected. In this constitution, a special space for the torque detector is not required, and the detecting effect is improved.