To prevent generation of strike noise of a housing member and a vane member by pushing a stopper piston constraining a rotating direction moving of a housing member and a vane member at a prescribed constraining location into a storage hole against energizing force of a spring and getting the stopper piston out of a stopper hole.

Force that a stopper piston 7 receives by hydraulic pressure works in a direction that the stopper piston 7 is pushed into the side of a chain sprocket 1 of a storage hole 8 against energizing force of a spring 18. Then, because a tip part 7c of the stopper piston 7 completely gets out of a stopper hole 20 of a front plate 4, a vane rotor 9 as a vane member is released in the constraint with a shoe housing 3 as a housing member. But, hydraulic force of lag angle hydraulic chambers 10, 11 acts on vane both side surfaces and the vane rotor 9 is held at a most lag angle location for the shoe housing 3. As a result, generation of strike noise of the vane rotor 9 and the shoe housing 3 can be prevented.