An impeller is equipped with: a disk part (30), having a cylindrical part (32) into which a rotary shaft (5) that rotates around an axis line (O) is inserted, with a portion of the cylindrical part in the axis line (O) direction of the rotary shaft (5) being fixed to the rotary shaft (35) as a grip part (33), and a disk main body part (35) extending from the cylindrical part (32) outward in the radial direction of the rotary shaft (5); a blade part (40) protruding from the disk main body part (35) toward a side in a first direction in the axis line (O) direction; a reinforcing member attachment part (50) formed on the cylindrical part (32) closer to a side in a second direction in the axis line (O) direction than the disk main body part (35); and a reinforcing member (53) formed of material having a higher specific strength than the disk part (30), and attached so as to cover the reinforcing member attachment part (50) from the outside.