To improve characteristics of a centrifugal fan by enlarging the surface area of blades while maintaining the size in a direction parallel to a rotation axis.SOLUTION: A centrifugal fan impeller 100 of the present disclosure comprises a ring 12, a back plate 14, and a plurality of fan blades 20 arranged around a rotation axis 10 between the ring 12 and the back plate 14. Each fan blade 20 has a radially-inner leading edge, a radially-outer rear edge, a first end coupled to the ring, a second end coupled to the back plate, and a front surface and a rear surface each of which is sectioned by the leading edge, the rear edge, the first end and the second end. Each of the front surface and the rear surface has a convex surface area in which curvature in the direction of the rotation axis 10 is positive, and a concave area in which curvature in the direction of the rotation axis is negative, and the convex surface area and the concave surface area are coupled to each other along the direction of the rotation axis.SELECTED DRAWING: Figure 1
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