PURPOSE: To prevent the transmission of the vibration of a back plate to a brake shoe by forming a ledge surface in the node part to the resonance generated on the upper back plate in the operation of a brake device.

CONSTITUTION: A brake shoe 2 is constituted of a web 4, shoe rim 5, and a lining 6, and the basic edge part of the web 4 is installed onto the anchor block 8 of a back plate 1, and one side part 5a of the shoe rim 5 is attached and supported onto the ledge surface 9 of the back plate 1. The ledge surface 9 is formed in conformity with the node part in resonance which is generated by the transmission of the brake torque acting between the brake shoe 2 and a brake drum 10 to the back plate 1. Therefore, the transmission of the vibration of the back plate 1 to the brake shoe 2, brake drum 10, etc., is prevented, and increase of the brake noise is prevented.