PURPOSE: To improve durability by installing a means for integrally forming an input/output shaft and a conical rotor, and transferring them to a turned state, setting the time when the output shaft revolution speed becomes equal to the input shaft revolution speed, as boundary, in a frictional continuously variable transmission equipped with the conical rotor as idle roller.

CONSTITUTION: As for a conical rotor 3, the conical surface 6 is friction-engaged with the inner peripheral surface of a speed change ring 4 which is interlocked with an output shaft 2, and the surface 7 on the opposite side to the conical surface 6 is friction-engaged with a transmission vehicle 8, which is pressing- urged by a frictional force generating device 9. In this case, a unidirectional clutch 12 is interposed between a bearing 11 supporting the shaft 10 of the conical rotor 3 and a transmission case 13. The unidirectional clutch 12 is put into a drive state, keeping the speed change ratio at 1 or less, and when the speed change ratio becomes equal to 1, the unidirectional clutch 12 is transferred to a nondrive state, and revolution is performed in the state where an input shaft 1, transmission wheel 8, bearing 11, reaction receiving roller 14, speed change ring 4, and an output shaft 2 are formed integrally.