A fan comprising: an impeller having a plurality of blades and rotating around a rotation axis; and at least one balance weight having a U-shaped opening portion and having at least one claw portion and attached to the impeller to correct a center of gravity of the impeller, wherein the impeller includes a circumferential concave-convex portion formed along a circumferential direction, the at least one claw portion being hooked on the circumferential concave-convex portion to restrict movement of the at least one balance weight in a radial direction of the impeller, and at least one radial concave-convex portion formed along the radial direction, the at least one claw portion being hooked on the at least one radial concave-convex portion to restrict movement of the at least one balance weight in the circumferential direction of the impeller, characterized in that the at least one claw portion comprises a plurality of claw portions, the at least one radial concave-convex portion comprises a plurality of radial concave-convex portions, the at least one balance weight has the plurality of the claw portions on a same surface, and when an interval between adjacent radial concave-convex portions of the plurality of radial concave-convex portions is D, and n is a natural number, a distance L between two of the plurality of claw portions on the same surface satisfies L≈(n+0.5)×D. an impeller having a plurality of blades and rotating around a rotation axis; and at least one balance weight having a U-shaped opening portion and having at least one claw portion and attached to the impeller to correct a center of gravity of the impeller, wherein the impeller includes a circumferential concave-convex portion formed along a circumferential direction, the at least one claw portion being hooked on the circumferential concave-convex portion to restrict movement of the at least one balance weight in a radial direction of the impeller, and at least one radial concave-convex portion formed along the radial direction, the at least one claw portion being hooked on the at least one radial concave-convex portion to restrict movement of the at least one balance weight in the circumferential direction of the impeller, a circumferential concave-convex portion formed along a circumferential direction, the at least one claw portion being hooked on the circumferential concave-convex portion to restrict movement of the at least one balance weight in a radial direction of the impeller, and at least one radial concave-convex portion formed along the radial direction, the at least one claw portion being hooked on the at least one radial concave-convex portion to restrict movement of the at least one balance weight in the circumferential direction of the impeller, characterized in that the at least one claw portion comprises a plurality of claw portions, the at least one radial concave-convex portion comprises a plurality of radial concave-convex portions, the at least one balance weight has the plurality of the claw portions on a same surface, and when an interval between adjacent radial concave-convex portions of the plurality of radial concave-convex portions is D, and n is a natural number, a distance L between two of the plurality of claw portions on the same surface satisfies L≈(n+0.5)×D.