Abstract: An infinitely variable transmission includes a driver shaft having a driver pulley, a driven shaft having a driven pulley, the driver and driven pulleys having fixed conical discs and movable conical discs, the movable conical discs having pressure chambers, an endless belt trained around said driver and driven pulleys, a device for supplying a fluid under pressure to the pressure chambers, a pressure regulating mechanism for regulating the fluid pressure at a prescribed pressure, and a fluid metering mechanism for regulating the amount of the fluid under the prescribed pressure in the pressure chambers. At least one of the pressure regulating mechanism and the fluid metering mechanism is disposed in the driver shaft or the driven shaft.