A secondary ion mass spectrometer (SIMS) has been added to a liquid metal source instrument which was designed as a micromachining apparatus. The SIMS performance rivals any reports to date on similar devices, even though no compromises were made with the primary function of the apparatus. End‐point detection for ion milling allows depth control within a few hundred angstroms, on micron sized raster fields. A sensitivity of 4×10 5cps/nA is routinely measured on52Cr+signals; similar count rates are also obtained from Al. Ion images on Cr or Al with sub‐micron resolution with a 25‐μm field are obtained in as little as 10 s collection time. Features as small as 0.3 μm can be defined by the secondary ion imaging, with the removal of only a few monolayers of material.