A toroidal type continuously variable transmission having first and second discs supported around a rotating shaft and receiving power rollers therebetween includes a ball spline having a first spline groove formed in an outer circumferential surface of the rotating shaft, a second spline groove formed in an inner circumferential surface of the first disc, and balls provided between the first spline groove and the second spline groove rollably. An axial position of an end portion of an effective groove portion of the first spline groove is located to correspond to an axial position of an inner end portion of the second spline groove or more closely to the second disc than the axial position thereof when a pressing unit, a preload spring and the first disc are installed around the rotating shaft, pressure oil is not fed to the pressing unit, and the preload spring is not elastically deformed.