Isotope dilution surface ionization mass spectrometry has been developed and applied to the determinations of alkalies, alkaline earth elements and heavy metals in environmental materials. The spiked sample is treated to reach the isotopic equilibrium in a mixture of acids at low temperature under pressure. The mass spectrometries for alkalies and alkaline earth elements are performed by applying the digest to a rhenium ionization filament, while heavy metals are determined after they have been transformed to the nitrates. By using a composite spike solution, concentrations of several elements are determined simultaneously. The present method can measure ng amounts of elements with an error of 1%.