A plurality of advanced angle chamber oil paths communicated to advanced angle hydraulic chambers and a plurality of retarded angle chamber oil paths communicated to retarded angle hydraulic chambers according to a change in rotating angle of a cam shaft are provided. The plurality of advanced angle chamber oil paths and the plurality of retarded angle chamber oil paths, respectively, are switched between communication and cut-off according to a rotating angle of the cam shaft. When torque in the direction of advanced angle acts in an advanced angle mode for phase shifting in the direction of advanced angle, the advanced angle hydraulic chambers are caused to communicate to a hydraulic power source and the retarded angle hydraulic chambers are caused to communicate to a drain. Also, at high speed of an engine, in the advanced angle mode, shut-off valves in the advanced angle chamber oil paths and the retarded angle chamber oil paths are opened so that hydraulic pressure is communicated from the hydraulic power source to the advanced angle chambers at all times in the same manner as in the related art.