A torque sensor is provided with: a magnetism generating section, which rotates with a first shaft; a rotating magnetic circuit section, which rotates with a second shaft; a fixed magnetic circuit section, which is fixed to a housing; a magnetic detector, which detects the density of a magnetic flux that is led from the magnetism generating section to the fixed magnetic circuit section through the rotating magnetic circuit section due to torsional deformation of a torsion bar; and a shielding plate, which is disposed between the rotating magnetic circuit section and the magnetic detector, and which magnetically shields the magnetic detector.