An ADMER (Atmospheric Dispersion Model for Exposure and Risk Assessment), which estimates atmospheric concentrations and the depositions of chemicals, has been developed. The ADMER includes some useful functions for calculations and for exposure and risk assessment, used for compiling meteorological data and making up gridded emission data for the simulation, and for analyzing calculated results visually using several kind of maps, charts and graphs, and estimating the size and location of populations exposed to chemicals. The ADMER will be useful for those risk assessments in which spatiotemporal distributions must be considered.