A control valve according to an exemplary embodiment includes an interlocking mechanism that achieves a first operation and a second operation simultaneously or continuously. In the first operation, a sub-valve is opened by having an actuating rod displaced integrally with a sub-valve element in accordance with the magnitude of solenoidal force. In the second operation, a load, by which to bias a main valve element in a closing direction of a main valve, is increased by displacing the actuating rod relative to the main valve element.