To provide a brake mechanism for a wire reel in a reinforcement binding machine improving a dustproofness.

A solenoid 32, a shaft 34 and a bracket 40 are arranged in a cover 17, and a part of the shaft 34 is positioned in the cylinder section 40A of the bracket 40, a bearing 35 and a hollow pin 38. Consequently, since a section between in the solenoid 32 and the brake means 30 of the solenoid 32 rotating a stopper lever 30 and the shaft 34 is covered with the cover 17, a brake is operated surely without attaching sand or the like on the internal section of the cover 17 even when the reinforcement binding machine is used in an outdoor section or the like. Accordingly, the adhesion of sand or the like on the solenoid 32 and the shaft 34 in the cover 17 is prevented without damaging the loading property of the wire reel, thus improving the dustproofness.