PURPOSE: To easily self-hold braking force in the position by freely fine-adjusting the braking force in the half braking releasing state when the non-excited braking state is manually released.

CONSTITUTION: An electromagnetic brake is composed of a movable iron core 3 for releasing the braking by being attracted by an electromagnet 1, and for braking in the axial direction by being pressed by a braking spring 2, a rotational disc 5 arranged between the movable iron core 3 and a braking plate 4, a center hub 6 to be axially and movably connected to the rotational disc 5 and a rotary shaft 7 for fixing the center hub 6 after penetrating the braking plate 4. And a manual releasing device is composed of an external thread 11 to be screw-connected to the center area of the electromagnet 1 and a releasing disc 12 arranged on the axial outside of the electromagnet 1, and for slidably holding the end surface of the braking spring 2. The releasing disc 12 is integrated with the external thread 11, and the releasing disc 12 is rotated, so as to fine adjust the length of the braking spring 2. It is possible to operate a code 13 wound around the releasing disc 12.