The present invention relates to a buckling restrained brace capable of absorbing vibration energy produced by an earthquake, wind power and the like, in a building and a steel structure.The buckling restrained brace of the present invention is accomplished by a buckling restrained brace 1 wherein a steel-made center axial member 3 is passed through a buckling-constraining concrete member 2 reinforced with a steel member 6, and an adhesion-preventive film 4 is provided to the interface between the steel-made center axial member and buckling-constraining concrete 5, the adhesion-preventive film showing a secant modulus in the thickness direction of at least 0.1 N/mm2 between a point which shows a compressive strain of 0% and a point which shows a compressive strain of 50%, and up to 21,000 N/mm2 between a point which shows a compressive strain of 50% and a point which shows a compressive strain of 75%, and having a thickness dt in the plate thickness direction of the steel-made center axial member and a thickness dw in the plate width direction thereof from at least 0.5 to 10% of the plate thickness t and from at least 0.5 to 10% of the plate width w, respectively, and by the application of the buckling restrained brace to a damping steel structure.