To reduce a variation in set torque, increase accuracy, eliminate the delay of working time, and simplify structure by eliminating the cause of friction in the steel ball and roller pressing or pressing force cutoff/holding mechanism in a torque limiter installed between a drive machine and a driven machine, cutting off torque of a specified level or higher, and protect the driven machine.

An inverse spring is adopted as the ball or roller pressing or pressing force cutoff/holding mechanism to transmit torque between the drive machine and the driven machine.