This volume contains full proceedings of the Fourth International Conference on Secondary Ion Mass Spectrometry (SIMS-IV), held in the Minoo-Kanko Hotel, Osaka, Japan, from November 13th to 19th, 1983. Coordinated by a local or ganizing committee under the auspices of the international organizing com mittee, it followed earlier conferences held in MUnster (1977), Stanford (1979), and Budapest (1981). The conference was attended by about 250 participants from 18 countries, and 130 papers including 24 invited ones were presented. Reflecting the rap idly expanding activities in the SIMS field,...