A canceling chamber with respect to the secondary cylinder of a CVT is eliminated and a hydraulic circuit is configured such that the line pressure (PL) operates directly on the secondary cylinder, with the line pressure (PL) flowing into/out of a primary cylinder through a control valve. When the vehicle speed (V) is below a prescribed vehicle speed (Vref), the lower limit (Nmin) of the number of rotations is set using an operating line (A) to achieve excellent fuel consumption; when the vehicle speed (V) exceeds the prescribed vehicle speed (Vref), the lower limit (Nmin) of the number of rotations of an input shaft is set using an operating line (B) that is shifted toward a higher number of rotations than the operating line (A) so as to set a speed change ratio that can be realized based on the line pressure (PL) that is set based on a required secondary pressure (Pss) from the torque on an output shaft. The speed change ratio (the number of input rotations) is changed within the range of this lower limit (Nmin) of the number of rotations.