PURPOSE: To prevent vibration and noise in the whole range of rotation from low speed rotation to high speed rotation without generating a rattle in a portion connected by a spline.

CONSTITUTION: An electromagnetic brake comprises a movable iron core 3 to be attracted by an electromagnet 1 so as to release a brake and brake in the axial direction by being depressed by a brake spring 2; a rotary disk 5 interposed between the movable iron core 3 and a brake plate 4 so as to be braked; a center hub 6 connected to the rotary disk 5 via a spline 6a; and a rotary shaft 7 inserted into the brake plate 4 so as to fix the center hub 6. A damper member made of an elastic material is disposed in a connected portion between the rotary disk 5 and the center hub 6 by the spline 6a. Particularly, the damper member is constituted of a rod member 11 disposed sideways the teeth of the connected portion by the spline 6a in the axial direction.