A three-way solenoid valve comprising: a valve body that is provided with an inlet, first and second outlets, a first valve seat positioned between the inlet and the first outlet, and a second valve seat positioned between the inlet and the second outlet; a first valve element that is movably disposed in the valve body so as to approach and be separated from the first valve seat; an electromagnetic actuator that drives the first valve element; and a second valve element that is movably disposed in the valve body so as to approach and be separated from the second valve seat, characterized in that the valve body includes a conduction hole that communicates with a back pressure chamber formed on a side of the second valve element opposite to the second valve seat, a third valve seat that is positioned between the conduction hole and the second outlet, a third valve element that is movably disposed so as to approach and be separated from the third valve seat, a biasing member that biases the third valve element toward the third valve seat, and an actuating member that is interposed between the first valve element and the third valve element, and when the first valve element is moved in the valve body by the electromagnetic actuator and approaches.or is separated from the first valve seat, the third valve element approaches or is separated from the third valve seat by the actuating member or the biasing member and differential pressure between the front and the rear sides of the second valve element is changed through the conduction hole, so that the second valve element approaches or is separated from the second valve seat. a valve body that is provided with an inlet, first and second outlets, a first valve seat positioned between the inlet and the first outlet, and a second valve seat positioned between the inlet and the second outlet; a first valve element that is movably disposed in the valve body so as to approach and be separated from the first valve seat; an electromagnetic actuator that drives the first valve element; and a second valve element that is movably disposed in the valve body so as to approach and be separated from the second valve seat, characterized in that the valve body includes a conduction hole that communicates with a back pressure chamber formed on a side of the second valve element opposite to the second valve seat, a third valve seat that is positioned between the conduction hole and the second outlet, a third valve element that is movably disposed so as to approach and be separated from the third valve seat, a biasing member that biases the third valve element toward the third valve seat, and an actuating member that is interposed between the first valve element and the third valve element, and when the first valve element is moved in the valve body by the electromagnetic actuator and approaches.or is separated from the first valve seat, the third valve element approaches or is separated from the third valve seat by the actuating member or the biasing member and differential pressure between the front and the rear sides of the second valve element is changed through the conduction hole, so that the second valve element approaches or is separated from the second valve seat.