A solenoid valve, in which a rod is moved by a plunger that comes into contact with and separates from a stator by electromagnetic force, causing a valve body that opens and closes a valve to move reciprocally, wherein a first space and a second space are formed at respective sides of the plunger in a movement direction of the plunger, a through-hole is formed in the plunger so as to be concentric with a center axis, the rod is arranged in the first space, and a communication passage is formed between an inner surface of the plunger and an outer surface of the rod and communicates with the first space and the second space, characterized in that the first space being positioned on a side of the valve body, the rod has a first part, a second part and a third part which are axially arranged from a side of the valve body toward a side of the plunger, the outer peripheral surface of the first part forms a circular surface in cross section extending over the entire circumference thereof, the outer peripheral surface of the second part has only one arc surface and one cutout surface or a plurality of arc surfaces and a same number of cutout surfaces as the plurality of arc surfaces, the outer peripheral surface of the third part has the same number of arc surfaces and cutout surfaces as the outer peripheral surface of the second part, each arc surface of the second part is flush with the circular surface of the first part, each arc surface of the third part is formed on an inner diameter side with respect to the arc surface of the second part, and each cutout surface of the second part is flush with the cutout surface of the third part angularly arranged at the same angle in the circumferential direction as the cutout surface of the second part, so as to collectively form one flat surface extending parallel to the axial direction, a fitting side end portion of the third part has a shape that tapers toward the end side in axial direction and has a tip that is formed to extend perpendicular to the axial direction, the second part and the third part are formed by notching a columnar rod member, when the number of cutout surfaces of each of the second part and the third part is plural, the cutout surfaces of each of the second part and the third part are formed to be equiangularly arranged in the circumferential direction, and the arc surface of the third part is arranged radially inward of the arc surface of the second part, and the arc surface of the third part and an axial end face of the second part forms a step portion. a first space and a second space are formed at respective sides of the plunger in a movement direction of the plunger, a through-hole is formed in the plunger so as to be concentric with a center axis, the rod is arranged in the first space, and a communication passage is formed between an inner surface of the plunger and an outer surface of the rod and communicates with the first space and the second space, characterized in that the first space being positioned on a side of the valve body, the rod has a first part, a second part and a third part which are axially arranged from a side of the valve body toward a side of the plunger, the outer peripheral surface of the first part forms a circular surface in cross section extending over the entire circumference thereof, the outer peripheral surface of the second part has only one arc surface and one cutout surface or a plurality of arc surfaces and a same number of cutout surfaces as the plurality of arc surfaces, the outer peripheral surface of the third part has the same number of arc surfaces and cutout surfaces as the outer peripheral surface of the second part, each arc surface of the second part is flush with the circular surface of the first part, each arc surface of the third part is formed on an inner diameter side with respect to the arc surface of the second part, and each cutout surface of the second part is flush with the cutout surface of the third part angularly arranged at the same angle in the circumferential direction as the cutout surface of the second part, so as to collectively form one flat surface extending parallel to the axial direction, a fitting side end portion of the third part has a shape that tapers toward the end side in axial direction and has a tip that is formed to extend perpendicular to the axial direction, the second part and the third part are formed by notching a columnar rod member, when the number of cutout surfaces of each of the second part and the third part is plural, the cutout surfaces of each of the second part and the third part are formed to be equiangularly arranged in the circumferential direction, and the arc surface of the third part is arranged radially inward of the arc surface of the second part, and the arc surface of the third part and an axial end face of the second part forms a step portion.