We have investigated the dependence of the depth resolution of Auger depth profiles of InP/ GaInAsP multilayer specimens on the sputtering rate, and the surface roughness caused by the ion bombardment. Ar ions having energies of 1.0 and 3.0kV were used for the sputtering. The depth resolution of the measured Auger depth profiles was improved by increasing the sputtering rate. Thus we obtained, by 3.0kv Ar ion sputtering, excellent Auger depth profiles with constant depth resolution from the outermost surface of the samples. We found that the obtained depth resolutions of the trailing edge group were largely different from those of leading edges in several specimens. We also found that the resulting resolution of Auger depth profiles could be determined by the surface roughness caused by the Ar ion sputtering.