Impeller

An impeller contributes to reducing manufacturing materials and improving characteristics. The impeller of the present invention rotates about a central axis extending in an axial direction, and includes: a base portion expanding in a radial direction; a plurality of blades which are arranged in the circumferential direction, extend from the inside in the radial direction to the outside in the radial direction, and have one end in the axial direction connected to the base part; and a ring part that connects end parts on the other side in the axial direction of the plurality of blades, in which the plurality of blades include: a first blade; and a second blade having a length greater than that of the first blade when viewed in the axial direction, the first blade and the second blade being alternately arranged in the circumferential direction, and a gap being formed between radial outer end portions of the first blade and the second blade which are adjacent in the circumferential direction. The sizes of the ci