PURPOSE: To reduce noise and prevent abrupt operation by including a brake shoe and applying resistance to the motion of an armature relative to an electromagnet by it to control and reduce speeds for applying and releasing brake.

CONSTITUTION: When a winding 17 of an electromagnet 13 is energized, an armature 14 is attracted toward a yoke 16 against the action of a spring 15 and the action of a brake shoe 34. An attraction force of the armature 14 is transmitted to a piston 36 by a handle part 39, the hydraulic fluid filled in a chamber 38a between the piston 36 and a main body 35 flows through a calibrated orifice 37 to bring a plate 51 into contact with the yoke 16, and the piston 36 is moved toward the main body 35 until pressures of hydraulic fluids on both sides of the piston 36 become the same. The brake 10 is brought to a release position in this way. That is, hammering noise of the armature 14 engaged with the yoke 16 is reduced in a brake release condition.