To perform the automatic shift operation of a continuously variable transmission with a simple constitution while the increase in the cost is controlled.

A control device is provided with an actuator 23 to give the assist force along the operation direction of a shift operation tool, operational condition detecting means 27, 28 to detect the operational direction of the shift operation tool and whether or not the shift operation tool is manually operated, and a control means 31 to perform the assist control which controls the actuator so as to give the assist force in the operational direction of the shift operation tool based on the detected information of the operational condition detecting means 27, 28. An engine load detecting means 50 to detect the load of an engine is provided, and the control means 31 controls the actuator 23 to perform the automatic shift operation of a continuously variable transmission so that the engine load is kept at the targeted load based on the detected information of the engine load detecting means 50.