A belt continuously variable transmission apparatus having a case which includes a power transmission case (which is part of a crankcase of an engine), a power transmission case cover, and an actuator cover assembled forwardly of the power transmission case cover (displaced forwardly on a vehicle body). The actuator cover is formed as a separate member from the power transmission case cover, and supports a motor for driving a movable part of a driving pulley. In addition, the actuator cover covers a gear system. The actuator cover is integrated with a cover of the water pump. The resulting configuration improves the assembling of the actuator cover of the belt continuously variable transmission apparatus.