To manufacture at a low cost by a simple structure and securely prevent a traveled material from meandering in a self-aligning roller used for a guide roller longitudinally traveling band-shaped sheet materials and belts such as a corrugated fiberboard.

This self-aligning roller is formed so that a support shaft 5 is passed through the inside of a cylindrical roller body 4 and the roller body is tiltably supported on a self-aligning bearing 6 fixedly mounted at the middle part of the support shaft. The self-aligning bearing uses roller bearings.