A way is described by which a commercial electric microbalance is converted into a highly sensitive torque magnetometer capable of measuring magnetic parameters of ferromagnetic thin films. The torque exerted on a thin film sample by a magnetic field is transmitted to the balance by means of a rod and a double armed frame; the frame has a low friction contact point with a support which prevents the loading of the balance. The noise level is 2 × 10⁻³ dyn cm and can be reduced to 2 × 10⁻⁴ dyn cm by connecting the transmitting system directly to the balance. Some characteristic torque curves exhibiting the performance of the instrument are given.