To provide a serpentine heat exchanger for an air conditioner, configured to effectively prevent reduction in heat exchange performance due to condensation, and to sufficiently respond to reduction in size of the air conditioner.

The serpentine heat exchanger 10 for an air conditioner is configured by: arranging a large number of fins 12 parallel to each other at intervals of 0.6-5.0 mm in a direction (y direction) orthogonal to a direction (x direction) in which air flows as a heat exchange fluid, to form a fin group 14; arranging the fin groups 14 in line in a direction (z direction) orthogonal to the x and y directions at a distance of 2.0 mm or less, to form multiple stages of fin groups 14; and arranging a heat transfer pipe 16 in a serpentine configuration so as to sequentially pass through the fin group 14 at each stage.