A torque sensor comprises a magnetic amorphous film (20) whose magnetostrictive characteristics vary with the amount of torque applied thereto and coils for detecting magnetostrictive variation disposed opposite the magnetic member. The torque sensor is constituted as an independent unit separate from the shaft (12) whose torque is to be measured. The independent unit comprises a tubular or a shaft member (10) having the magnetic amorphous film attached thereto and a housing (46) with the coils at its inner wall. The housing covers the tubular or shaft member and is rotatably mounted with respect to the member. The tubular or shaft member is easily mounted on the shaft through spline fitting (24,26).
