A blower includes a fan; and an air duct having a passage formed therein, the air duct guiding the air and blowing the air onto the corona discharger, the air duct including an increasing-width portion in which a passage width gradually increases downstream in an air flow direction, a decreasing-height portion in which a passage height gradually decreases downstream in the air flow direction, an extension portion extending from a downstream end of the decreasing-height portion to a position near the corona discharger, a bent portion that is bent from a downstream end of the extension portion toward the corona discharger, an opening formed at a downstream end of the bent portion, and a plate-shaped member disposed in the passage at a position on an inner wall of any of the decreasing-height portion and the extension portion, the inner wall being on the corona discharger side.