A controller of a toroidal continuously variable transmission (10, 410) in which a transmission ratio is continuously changed depending on a roller position of a power roller, the controller comprising: a hydraulic actuator which changes the roller position; a position control unit (72, 372) which outputs a driving signal to the hydraulic actuator to control the roller position; and a position estimation unit which estimates the roller position based on an output value of the driving signal, wherein the hydraulic actuator includes a biasing mechanism which forcibly keeps the roller position at a predetermined position in a case where the driving signal meets a predetermined condition, wherein during start-up of the toroidal continuously variable transmission, the position control unit (72, 372) is configured to perform a start-up control before the position control unit (72, 372) performs a normal control in which an output value of the driving signal is derived based on a deviation (ΔX) between a command value of the roller position (Xref) and an estimated value of the roller position (^X) which is estimated by the position estimation unit, wherein during the start-up control, the position control unit (72, 372) is configured to output the driving signal to reciprocate a spool of the hydraulic actuator in a case where a temperature of hydraulic oil supplied to the hydraulic actuator is lower than a reference temperature, and output the driving signal which meets the predetermined condition to keep the roller position at the predetermined position in a case where the temperature of the hydraulic oil has become equal to or higher than the reference temperature thereafter, characterised in that the position estimation unit is configured to set the predetermined position to an initial value of the estimated value, when the start-up control is terminated and the normal control is initiated. a hydraulic actuator which changes the roller position; a position control unit (72, 372) which outputs a driving signal to the hydraulic actuator to control the roller position; and a position estimation unit which estimates the roller position based on an output value of the driving signal, wherein the hydraulic actuator includes a biasing mechanism which forcibly keeps the roller position at a predetermined position in a case where the driving signal meets a predetermined condition, wherein during start-up of the toroidal continuously variable transmission, the position control unit (72, 372) is configured to perform a start-up control before the position control unit (72, 372) performs a normal control in which an output value of the driving signal is derived based on a deviation (ΔX) between a command value of the roller position (Xref) and an estimated value of the roller position (^X) which is estimated by the position estimation unit, wherein during the start-up control, the position control unit (72, 372) is configured to output the driving signal to reciprocate a spool of the hydraulic actuator in a case where a temperature of hydraulic oil supplied to the hydraulic actuator is lower than a reference temperature, and output the driving signal which meets the predetermined condition to keep the roller position at the predetermined position in a case where the temperature of the hydraulic oil has become equal to or higher than the reference temperature thereafter, output the driving signal to reciprocate a spool of the hydraulic actuator in a case where a temperature of hydraulic oil supplied to the hydraulic actuator is lower than a reference temperature, and output the driving signal which meets the predetermined condition to keep the roller position at the predetermined position in a case where the temperature of the hydraulic oil has become equal to or higher than the reference temperature thereafter, characterised in that the position estimation unit is configured to set the predetermined position to an initial value of the estimated value, when the start-up control is terminated and the normal control is initiated.