A three-way electromagnetic valve comprising: a valve main body provided with an inflow port for communicating with a heat exchanger of a heat pump apparatus, a first outflow port for communicating with an expansion mechanism of said heat pump apparatus, a second outflow port for communicating with an intake port of a compressor of said heat pump apparatus, a first valve seat positioned between said inflow port and said first outflow port, and a second valve seat positioned between said inflow port and said second outflow port, the second valve seat being arranged so that a valve bore of the second valve seat and a valve bore of the first valve seat are opposed to each other and are positioned between the first valve seat and the second valve seat; a first valve body arranged at an opposed position with respect to said first valve seat within said valve main body; a coil spring interposed between a lid closing a lower opening of the valve main body and the first valve body and provided to bias said first valve body toward said first valve seat; a second valve body having two through-holes (7a, 7b), the second valve body being arranged at an opposed position with respect to said second valve seat within said valve main body; an electromagnetic coil provided to enable closing of one through-hole of the two through-holes (7a, 7b) provided in the second valve body; and at least two actuating members (9, 9A, 9B) interposed between said first valve body and said second valve body, wherein the first valve seat is communicated, at a side of the first valve body, with the inflow port, and the second valve seat is communicated, at the second valve body, with the inflow port, wherein the first valve seat is communicated, at a side of the valve bore thereof, with the first outflow port, and the second valve seat is communicated, at a side of the valve bore thereof, with the second outflow port, wherein the seating of said second valve body on said second valve seat is carried out by energizing said electromagnetic coil, and the seating of said first valve body on said first valve seat is carried out by de-energizing the electromagnetic coil and by a biased force of said coil spring, wherein when the second valve body is seated on said second valve seat, a movement of the second valve body is transmitted via said at least two actuating members (9, 9A, 9B) to the first valve body, causing the first valve body to move away from the first valve seat, and wherein the valve bore diameter of said first valve seat is made smaller than the valve bore diameter of said second valve seat. a valve main body provided with an inflow port for communicating with a heat exchanger of a heat pump apparatus, a first outflow port for communicating with an expansion mechanism of said heat pump apparatus, a second outflow port for communicating with an intake port of a compressor of said heat pump apparatus, a first valve seat positioned between said inflow port and said first outflow port, and a second valve seat positioned between said inflow port and said second outflow port, the second valve seat being arranged so that a valve bore of the second valve seat and a valve bore of the first valve seat are opposed to each other and are positioned between the first valve seat and the second valve seat; a first valve body arranged at an opposed position with respect to said first valve seat within said valve main body; a coil spring interposed between a lid closing a lower opening of the valve main body and the first valve body and provided to bias said first valve body toward said first valve seat; a second valve body having two through-holes (7a, 7b), the second valve body being arranged at an opposed position with respect to said second valve seat within said valve main body; an electromagnetic coil provided to enable closing of one through-hole of the two through-holes (7a, 7b) provided in the second valve body; and at least two actuating members (9, 9A, 9B) interposed between said first valve body and said second valve body, wherein the first valve seat is communicated, at a side of the first valve body, with the inflow port, and the second valve seat is communicated, at the second valve body, with the inflow port, wherein the first valve seat is communicated, at a side of the valve bore thereof, with the first outflow port, and the second valve seat is communicated, at a side of the valve bore thereof, with the second outflow port, wherein the seating of said second valve body on said second valve seat is carried out by energizing said electromagnetic coil, and the seating of said first valve body on said first valve seat is carried out by de-energizing the electromagnetic coil and by a biased force of said coil spring, wherein when the second valve body is seated on said second valve seat, a movement of the second valve body is transmitted via said at least two actuating members (9, 9A, 9B) to the first valve body, causing the first valve body to move away from the first valve seat, and wherein the valve bore diameter of said first valve seat is made smaller than the valve bore diameter of said second valve seat.