PURPOSE: To improve the high temp. strength and high temp. deformation resistance of the fin material and to permit its thinning by specifying the recrystallizating grain size and the ratio of the length of the crystal grains in the rolling direction to the thickness.

CONSTITUTION: The aluminum alloy fin material is so formed that ≥200μm recrystallization grain size and ≥20 aspect ratio (l)/(d) (where (l) denotes the length of the crystal grains in the rolling direction and (d) denotes the thickness) are simultaneously satisfied. The fin material is used to a fin for a heat exchanger as a bare material or the core material of a brazing sheet.