PURPOSE: To make a torque cell compact and easily attach the torque cell to the various types of rolling mills.

CONSTITUTION: Through holes 72, 73 along the axial line are provided on the shafts 70, 71 of a reduction gear 56. The torque cells 60, 61 are connected between these shafts 70, 71 and universal joints 57, 58. The torque cells have strain generating bodies 80 generating the strain in accordance with torque applied to rolling rolls 43, 44 and strain gages 81 transforming the magnitude of the strain generated on the strain generating bodies 80 into an electrical signal. Slip ring mechanisms 100, 101 having electrically conductive rings and brushes are provided in the end parts of the shafts 70, 71. Lead wires 95 which are connected to the strain gages 81 are led from one end side to the other end side of the shafts 70, 71 through the through holes 72, 73 and electrically connected to the electrically conductive rings of the slip rings 100, 101.