To improve actuation responsiveness of a valve stopping mechanism 14 using working fluid discharged from a second phase changing mechanism 12.

A V-type 8-cylinder internal combustion engine of a one-plane crankshaft type is composed in such a way that the cylinders on one bank can rest, a valve stopping mechanism 14 is provided, and the second phase changing mechanism 12 sharing an oil pump 10 is provided. When resting of the cylinders is started, the second phase changing mechanism 12 is simultaneously actuated to the advance side. A circulation oil passage 48 is provided to supply working fluid discharged from the second phase changing mechanism 12 at the time of this advance action to the valve stopping mechanism 14, thereby responsiveness of the valve stopping mechanism 14 is improved.