A 6000-series aluminum alloy plate, which is obtained by introducing a minor amount of Sn into a 6000-series aluminum alloy plate that has a specific Mg and Si composition, and controlling the tissue of the plate on the basis of the tissue thereof under a specific heat treatment, shows an improved hem bendability even after aging for a long period of time at room temperature, as a characteristic after the natural aging, and increases the bake hardenability (BH response) in baking finishing a molded automobile panel.