Fin, heat exchanger with fin, and method of manufacturing fin

A method of manufacturing a corrugated fin in which peak portions and valley portions extending along a first direction are arranged alternately in a second direction perpendicular to the first direction, the method comprising:

• preparing a metal plate that has a flat shape;
• shaping the metal plate into a corrugated shape by sandwiching the metal plate by a first roller and a second roller, wherein
• the shaping includes compressing at least a part of the metal plate that is to be inclined portions by the first roller and the second roller such that a thickness of the metal plate at each apex of the peak portions and the valley portions is larger than a thickness of the inclined portions of the metal plate that connects the peak portions and the valley portions adjacent to each other, thereby the part of the metal plate becomes thin;
• and
• correcting a height of the corrugated fin between the peak portions and the valley portions to uniform the height of the corrugated fin by sandwiching the corrugated fin, in which the peak portions and the valley portions have been formed, between a third roller and a fourth roller after the shaping, such that a thickness at each apex of the peak portions and the valley portions is larger than a thickness of the inclined portions that connect the peak portions and the valley portions adjacent to each other.