A heat exchanger aluminum alloy fin material, comprising Si 0.5 to 1.5 mass %; Fe 0.1 to 1.0 mass %; Mn 0.8 to 2.2 mass %; Zn 0.4 to 2.5 mass %; and further at least one selected from Cu, Ti, Zr, Cr, and V each in 0.02 to 0.3 mass %, with the balance being Al and unavoidable impurities, wherein a metallographic microstructure before braze-heating is such that a density of second phase particles having a circle-equivalent diameter of less than 0.1 μm is less than 1×107 particles/mm2, and that a density of second phase particles having a circle-equivalent diameter of 0.1 μm or more is 5×104 particles/mm2 or more, wherein a tensile strength before braze-heating, TSB, a tensile strength after braze-heating, TSA, and a sheet thickness of the fin material, t, satisfy: 0.4≦(TSB−TSA)/t≦2.1, and wherein the sheet thickness is 150 μm or less.