According to dynamical theory of electron diffraction, the incident electron density distribution, or “wave-field”, was calculated for a parallel-dimer structure of Si(001)2×2-Al surface on the condition of medium-energy electron diffraction (MEED). The surface structure and the calculated method were confirmed to be effective by the rocking-curve analysis of diffracted beam intensity. The wave-field at the surface is very sensitive to changes in diffraction conditions, such as the incident glancing angle. The Al(LMM) Auger electron intensity emitted from the Si(001)2×2-Al surface during MEED incident beam rocking, that is named beam rocking Auger electron spectroscopy (BRAES), has been found to be correlated to the calculated wave-field intensity on the Al atomic rows. The BRAES profile of adsorbate Al(LMM) differs from that of substrate Si(LVV). [DOI: 10.1380/ejssnt.2009.97]