To provide a simply-structured tension adjuster having respective adjusting functions for major width adjustment in replacement, usual minor adjustment, and meandering adjustment and easily releasing tension in replacement and to provide a game ball lifting and polishing device using this tension adjuster.

A mechanism adjusting tension applied to a lifting belt is constructed of a tension main adjustment part 100 coping with major tension adjustment in replacement and a tension minor adjustment part 200 for adjusting tension finely. The tension main adjustment part 100 is arranged in the upper part of a standing frame 22 while the tension minor adjustment part 200 is arranged in the lower part apart from the tension main adjustment part 100. In the tension minor adjustment part 200, a meandering adjusting roller 220 moves its one end upward and downward while using the other end as an original point so as to change an inclination, and the meandering adjusting roller and a guide roller 250 pressing the lifting belt from the outside are supported rotationally forward while using one side ends as original points and displaced to a pressure releasing condition when screws stopping the other side ends are removed.