PURPOSE: To provide a torque limiter in which the torque can be regulated without altering the entire length.

CONSTITUTION: A first rotary shaft 1 with a permanent magnet 3 fixed to the outer periphery 11 and a second rotary shaft 2 with a semicured magnetic element 4 to the inner periphery 21 are so disposed that the magnet 3 is opposed to the element 4, and so integrally assembled as to be relatively rotatable. The press-fit degree is altered to vary the opposed area between the magnet and the element, thereby regulating the hysteresis torque. Thus, the torque can be easily regulated. Since the entire length of a torque limiter is not changed, the structure of the machine side for mounting the limiter can be simplified. The limiter also becomes a simple structure, and the productivity is improved to reduce the cost.