A blower fan includes a motor unit including a rotary unit; a plurality of blades fixed to an outer surface of the rotary unit and arranged to be rotated about a center axis by the motor unit; and a lower plate portion defined by a magnetic body and positioned below the motor unit and the blades. The lower plate portion includes a motor fixing portion, a curved portion, a peripheral portion, and a plurality of ribs arranged to interconnect the motor fixing portion and the peripheral portion either directly or through the curved portion, the curved portion including a standing portion extending upward from the outer edge portion of the motor fixing portion and an upper surface portion extending radially outward from an upper end of the standing portion, a plurality of openings positioned below the blades being defined by the curved portion, the peripheral portion, and the ribs.