To provide a deenergization electromagnetic brake that is releasable by an operation of a manual release lever even from outside a brake cover.

The deenergization electromagnetic brake is so constructed that a rotor 1 as a rotary part is unlocked when an electromagnet 3 is energized to attract thereto an armature 4 against spring force and when a manual release lever 9 is inclined to press the armature 4 manually on the electromagnet 3. A release rod 15 mounted on a brake cover 9 turnably on a vertical axis is passed through and projected out from the brake cover 10 enclosing the overall mechanism including the manual release lever 9. An external turning movement of the release rod 15 can operate the manual release lever 9 via a cam 16 mounted on the release rod tip to release the brake.