PURPOSE: To conduct the speed change operation of a belt type continuously variable transmission at a speed faster than the normal operating speed by conducting the speed change operation of the belt type continuously variable transmission via the operating force of an operation lever, and directly operating a cam type operation mechanism preferentially to an assist mechanism with the operation lever.

CONSTITUTION: This belt type continuously variable transmission is provided with an assist mechanism A operating a cam type operation mechanism 15 changing the split width interval of a split pulley 13 based on the detection information of an operation lever 21 by an operating direction detecting means As. The cam type operation mechanism 15 is constituted of an assist operation system having a shift fork 15C sliding a shift member 15B via the action of the assist mechanism A and a manual operation system having a cam member 15A directly sliding the shift member 15B via the action of the operation lever 21 preferentially to the assist mechanism A. The point of application (a) of the shift fork 15C to the shift member 15B is set near the pressing point of application (b) of a transmission belt 14 to the split pulley 13.