Excellent in paint bake hardenability aluminum alloy sheet

One object of the present invention is to provide both the BH property after long-term aging at room temperature, 6000 series aluminum alloy sheet formability after long-term aging at room temperature. In one embodiment of the present invention, a 6000 series aluminum alloy containing Sn plate comprises at least a certain number of specific density of clusters of BH effect, the particular cluster to determine three-dimensional atom probe field ion microscope, and by consistent aggregate of atoms so as to satisfy these conditions the mean size of the radius of the circle equivalent diameter is in a certain range, and to reduce the standard deviation of the radius of the circle equivalent diameter of the BH properties after long-term aging at room temperature further improved.