The rotary motion of a camshaft is transmitted from a first drive cam to a slide surface of a swing cam arm via intermediate members so that the swing cam arm lifts a valve. In this instance, the operating characteristic of the valve changes when the rotation position of a control shaft changes to change the positions of the intermediate members on the slide surface. When the operating characteristic control mode for the valve is to be changed from variable control to fixed control, coupling means couples the swing cam arm and input arm, thereby causing a second drive cam to swing the swing cam arm. The setting for the lift amount of the valve that is obtained when the second drive cam swings the swing cam arm is not smaller than a maximum lift amount setting for a situation where the first drive cam swings the swing cam arm.