PURPOSE: To miniaturize a hysteresis brake, by forming a braking frame section which faces a permanent magnet with magnetic clearance interposed, out of a magnetic material predominate in magnetic hysteresis characteristic.

CONSTITUTION: A braking frame 11 is composed of a frame body 12 and a frame lid 13 to fix to one of its edges. The frame body 12 is almost cylindrical and is and of magnetic substance predominate in magnetic hysteresis characteristic, e.g. (non-magnetized) martensite stainless steel such as SUS 410, etc. Inside the other edge of the frame body 12 is installed a bearing 14, while a bearing 15 is installed to the frame lid 13, too, with which a shaft 17 of a rotor 16 is supported. A permanent magnet 19 is installed to the rotor 16 through a yoke 18. The outside circumference of this magnet 19 stands close to face the inside circumference of the frame body 12 through magnetic clearance 20. Hence, as the frame body 12 is ready to get magnetized. brake torque can be obtained without need of exciting coils.