The invention discloses an electromagnetic brake arranged on a rotary mechanism and used for braking the rotary mechanism. The electromagnetic brake comprises a driving mechanism, an armature and a friction plate. The friction plate can rotate along the rotary mechanism. The armature is arranged between the driving mechanism and the friction plate. The armature can abut against the friction plateor can be separated from the friction plate under the action of the driving mechanism. When the armature abuts against the friction plate, the rotary mechanism is braked. The face, matched with the friction plate, of the armature is not perpendicular to the axis of the driving mechanism. According to the electromagnetic brake provided by the invention, the face, matched with the friction plate, ofthe armature is not perpendicular to the axis of the driving mechanism, thus the friction area between the armature and the driving mechanism is increased, needed friction force can be obtained underthe condition that the driving mechanism provides smaller driving force, and the size of the driving mechanism can be smaller accordingly.