To reduce an increase of the hydraulic pressure of hydraulic oil required for moving a valve element.

This belt type continuously variable transmission 110 is provided with a primary hydraulic pressure chamber hydraulic oil supply amount adjustment device 70 in which a pressure reception surface arranged on a primary shaft 51 and receiving a force is formed along a rotary shaft, and which is used for adjusting the flow rate of hydraulic oil supplied to a primary hydraulic oil chamber 54 by moving a ball 74 closing an opening of a passage for running the hydraulic oil therethrough by a force imposed on the pressure reception surface in the direction of rotation using the rotary shaft as an axis.