To provide a structure of a distributing valve capable of positively venting the distributing valve used for a speed governor of a hydraulic turbine and the like, and a structure of the distributing valve facilitating machining/assembling of the distributing valve.

The distributing valve is structured so as to make a moving direction of a plunger 16 of the distributing valve horizontal, and an air-venting valve 37 is disposed on the uppermost portion of each port a, b, c of the distributing valve. The distributing valve is structured so as to make the moving direction of a plunger 16 of the distributing valve horizontal, and the plunger 16 and controlling pistons 18, 20 are made in a separated structure. And the controlling pistons 18, 20 are disposed on both ends of the plunger 16.