Standardization of depth profiling using XPS, AES, and SIMS has been discussed and developed by ISO/TC 201/SC 4. So far this committee published one standard and one technical report, and the latter is a generally informative summary of depth profiling and the former is a standard for the optimization of ion sputtering. In this standard, the described most important procedure is the alignment of specimens, incident probes, and analyzers and we should pay attention to the probe diameter and scanning area even for the same analysis technique. It is also important to optimize the depth resolution by adjusting the ion accelerating energy, ion species, incident angle, and so on. The experimental parameters are listed in this report and the reference materials are also shown, which are certified in several countries. The mesh-replica method is introduced, that has been discussed in ISO/TC 201/SC 4 and it is very useful to determine the actual sputtering rate.