HEAT EXCHANGER

PURPOSE:To prevent small fins from bending when a bending work is performed to a heat exchanger even if the small fins are made thin, by performing rib works to the flat parts between cutouts in slits or in louvers of small fins. CONSTITUTION:Pipes for heating medium 23 are arranged staggeredly, crossing at right angles to small fins 22. A heat exchanger 21 is manufactured by bending part of a component composed of the small fins 22 and the pipes for heating medium 23. Rib works are performed on the flat parts between cutouts 22a in slits or in louvers of small fins 22. By performing such works, the bodies of fins 22 are reinforced, and even if the fins 22 are made thin, they are prevented from bending at parts where the fins 22 are in contact with a mold tool 5 for bending when a bending work is applied to the heat exchanger 21.