There is provided a very reliable three-way solenoid valve that can reliably switch a refrigerant flow passage while ensuring a refrigerant flow rate even under a large-differential pressure environment without increasing the size of an electromagnetic coil and the like.A valve body includes a conduction hole that communicates with a back pressure chamber formed on a side of a second valve element opposite to a second valve seat, a third valve seat that is positioned between the conduction hole and a second outlet, a third valve element that is movably disposed so as to approach and be separated from the third valve seat, a coil spring that biases the third valve element toward the third valve seat, and actuating rods that are interposed between a first valve element and the third valve element.