PURPOSE: To highly reliably make braking and stopping a rotary body by strong braking force with the rotation force of the rotary body transmitted to a fixed structure by generating electromagnetic force with a coil excited by D.C. current, and slidedly contacting a sliding member to the rotary body with the electromagnetic force interlinked to magnetic flux.

CONSTITUTION: Magnetic flux is generated from an inner peripheral side toward an outer peripheral side in most parts of respective permanent magnets 33a and 33b, a cylinder 30, and respective coils 22a and 22b along a magnetic circuit 41 when a brake is in an open condition. Supplying D.C. current to the coils 22a and 22b with a D.C. power source control device 26 in this condition, causes generating electromagnetic force in them to be acted downward. However since the coils 22a and 22b are supported with a fixed structure 21 via a spacer 23, reversely a movable member, composed of the permanent magnets 33a and 33b, a cylinder 30 and a cylinder fitting member 31 supporting the permanent magnets 33a and 33b, and a shoe receiver 27 and a shoe 28, is raised to slidedly contact the shoe 28 to a rotary body 29. Consequently the rotation force of the rotary body 29 is transmitted to the fixed structure 21 to be braked.