An induction torque motor, TM, comprising: a stator; and a rotor, the rotor comprising: a shaft member; and a cylindrical member concentrically connected to the shaft member, the cylindrical member being formed of a soft magnetic material having a specific electric resistivity lower than or equal to 0.4 μΩ·m and a relative permeability higher than or equal to 1000 and lower than or equal to 50000, wherein: let T be the torque of the induction torque motor, TM, in N·m, let P be the eddy current loss of the rotor in W/kg, let s be the slip of the induction torque motor, TM, let f 0 be the drive frequency of the induction torque motor, TM, in Hz, let ρ be the specific electric resistivity of the soft magnetic material in μΩ·m, let μ be the relative permeability of the soft magnetic material, and let δ(sf 0) be the skin depth of the cylindrical member at a drive frequency of f 0 in m, and when a symbol oc in a mathematical statement "A oc B" indicates that A is proportional to B, the torque T per "loss P/slip sf 0 " is defined as: T / P / sf 0 ∝ 1 / 1 + a / μ ⋅ δ sf 0 / ρ the parameter a in the previous equation is inversely proportional to a distance G between the outer peripheral surface of the cylindrical member of the rotor and the inner peripheral surface of the stator, the induction torque motor, TM, being characterized in that the distance G is in a range 0.1 mm ≤ G ≤ 0.15 mm defining the parameter a as being in the range 1000 ≤ a ≤ 2500. a stator; and a rotor, the rotor comprising: a shaft member; and a cylindrical member concentrically connected to the shaft member, the cylindrical member being formed of a soft magnetic material having a specific electric resistivity lower than or equal to 0.4 μΩ·m and a relative permeability higher than or equal to 1000 and lower than or equal to 50000, a shaft member; and a cylindrical member concentrically connected to the shaft member, the cylindrical member being formed of a soft magnetic material having a specific electric resistivity lower than or equal to 0.4 μΩ·m and a relative permeability higher than or equal to 1000 and lower than or equal to 50000, wherein: let T be the torque of the induction torque motor, TM, in N·m, let P be the eddy current loss of the rotor in W/kg, let s be the slip of the induction torque motor, TM, let f 0 be the drive frequency of the induction torque motor, TM, in Hz, let ρ be the specific electric resistivity of the soft magnetic material in μΩ·m, let μ be the relative permeability of the soft magnetic material, and let δ(sf 0) be the skin depth of the cylindrical member at a drive frequency of f 0 in m, and when a symbol oc in a mathematical statement "A oc B" indicates that A is proportional to B, the torque T per "loss P/slip sf 0 " is defined as: T / P / sf 0 ∝ 1 / 1 + a / μ ⋅ δ sf 0 / ρ the parameter a in the previous equation is inversely proportional to a distance G between the outer peripheral surface of the cylindrical member of the rotor and the inner peripheral surface of the stator, the induction torque motor, TM, being characterized in that the distance G is in a range 0.1 mm ≤ G ≤ 0.15 mm defining the parameter a as being in the range 1000 ≤ a ≤ 2500.