In an oil flow control valve (OCV) according to the present invention, a first volume varying chamber is adapted to communicate with a second volume varying chamber through a second plunger breathing path, and the second volume varying chamber is adapted to communicate with a first breathing hole through an intra-plunger breathing path, an intra-shaft breathing path, and a third volume varying chamber. That is, the breathing path to the second volume varying chamber is long and the volume thereof is large, and the breathing path to the first volume varying chamber is still longer and larger in its volume. Consequently, the amount of foreign matters getting into the first and second volume varying chambers can be decreased and therefore it is possible to prevent the occurrence of an operation defect of the OCV.