To improve efficiency of regenerating electric power, while suppressing physical size increase of a hybrid system.

A continuously variable transmission includes a sun roller 11 connected with an engine 51 and having an outer circumferential surface inclined in an axial direction, a plurality of planetary balls 14 on the outer circumferential surface, a carrier 15 holding the respective planetary balls 14 to enable rotation and inclination of the respective planetary balls 14, first and second rotating members 12, 13 connected with a first motor/generator 52 and a drive wheel W, respectively, and capable of rotation with a rotation center axis of the sun roller 11 as the center while the respective planetary balls 14 are held, a first helical gear 41 rotating integrally with the sun roller 11, and a second helical gear 42 on the engine 51 side meshed with the first helical gear 41, and the first and second helical gears 41, 42 are configured so that the sun roller 11 is moved in an axial direction away from the respective planetary balls 14 by thrust force during being driven.