A fin manufacturing method and apparatus includes: a first inter-row slit device that forms, by forming in a thin metal plate having a plurality of openings a plurality of slits extending in a longitudinal direction of the thin metal plate while leaving an uncut portion between the plurality of slits, metal strips partially coupled to each other in a transverse direction; a feed roller and a feeding device that convey, in the longitudinal direction, the metal strips in which the plurality of slits is formed by the first inter-row slit device; and a stacking device that (i) forms fins by cutting the uncut portion via which the metal strips are coupled to each other, to separate the metal strips and by cutting the metal strips at regular length intervals and (ii) stacks the formed fins.