Effects of calcination on catalytic activity for steam reforming of methanol (SRM) over an Al-Cu-Fe quasicrystal (QC) leached with NaOH aq. have been investigated in terms of microstructure with X-ray diffraction and transmission electron microscope (TEM). Calcination at 600 A degrees C in air drastically improved the catalytic activity of the leached QC. TEM observations on cross-section of the samples revealed that cubic Cu (x) Fe3-x-y Al (y) O-4 spinel was formed at the outermost layer of the leached QC after calcinations. Prior to the catalytic reaction, the Cu (x) Fe3-x-y Al (y) O-4 spinel decomposed to a composite where fine Cu nanoparticles dispersed in (Fe,Al)(3)O-4 matrix under H-2 treatment at 300 A degrees C. Drastic increase in catalytic activity is responsible for the fine Cu nanoparticles in the composite. The Cu nanoparticles sit along the same orientation with (Fe,Al)(3)O-4, e.g., Cu [013]//(Fe,Al)(3)O-4 [013] and Cu [200]//(Fe,Al)(3)O-4 [400]. This orientation relationship may stabilize the Cu nanoparticles through a bonding of Cu-O-Fe.