This alloyed hot-dip galvanized steel plate comprises a steel plate, a galvanization layer on the surface thereof, and a mixed layer formed between the steel plate and the galvanization layer. The mixed layer contains the following: a ferrite part that has microscopic crystal grains that are more than 0 [mu]m but no more than 2 [mu]m in size; a zinc-iron alloy phase; and an oxide that contains one or more elements selected from among manganese, silicon, aluminum, and chromium. Said oxide and zinc-iron alloy phase are present at the grain boundaries of the microscopic crystal grains in the mixed layer, and tendrils of the zinc-iron alloy phase extend into the ferrite part,(formula 1) [Mn]+[Si]+[Al]+[Cr] >= 0.4.