PURPOSE: To make the structure of a shuttle valve simple by making the piston heads and valve seats cooperate, the valve open position supplying hydraulic pressure to one of the operating hydraulic manipulators while the other valve close position cutting off the pressure supply to the other hydraulic manipulator.

CONSTITUTION: A piston 3 is arranged in the continuous bore 2 of a shuttle valve housing 1, and the conical head 4a, 4b of the piston ends 3a, 3b cooperate with valve seats 5a, 6c of high pressure fittings 5, 6. When the manipulators 7, 8 are not used and a pressure generator 9 is in operation, the hydraulic fluid passes through the high pressure fittings 5, 6 and the manipulator manual valves 7a, 8a and returns to an oil vessel 13. When both of the manipulators 7, 8 are used at the same time, the piston 3 is position at the intermediate position, and the hydraulic fluid is guided uniformly to the manipulators 7, 8. When only the manipulator 7 is used and the piston is positioned as illustrated, the manipulator 8 is cut off from pressure supply from the pressure generator 9 while the other manipulator 7 receives pressure supply. Thus, the shuttle valve can be made simple in structure allowing easy production and storage.