We demonstrated high temperature glancing deposition (HT-GLAD) of Al on the heated substrate with trench patterns. When Al was deposited under the condition, where the Al vapor is incident at very glancing on the sidewall but on the surface, Al nano-whiskers grew only on the sidewall of the trenches since HT-GLAD condition is achieved only for the sidewall. On the other, Al was deposited at glancing angle both on the surface and the sidewalls, nano-whiskers grow both on the surface and the sidewalls of the trenches. The selective growth of the nano-whisker is successfully achieved by controlling the geometrical deposition conditions. Remarkably, moreover, the nano-whiskers grow not only on the illuminated sidewalls but also on the shadow sidewall. In addition, few nano-whiskers grow on the shadow region of the bottom of the trenches. In order to understand the peculiar growth of Al nano-whiskers, novel transport processes of Al atoms other than the surface diffusion have to be clarified. The reevaporation or reflective scattering on the sidewalls of the trenches is likely to play an important role in the growth of nano-whiskers.