Low-cost, easy-to-use, and reliable sensor devices for air pollutants are developed rapidly in recent years. In this training workshop, the application of this type of sensors in the exposure assessment, environmental epidemiology, and indoor air quality will be introduced. How to use PM2.5 sensor devices in combination with exposure modeling in the field of exposure and epidemiology will be presented. In addition to lectures, participants will also have the opportunity to learn how to assemble and operate the low-cost sensors developed in Taiwan and Hong Kong. Moreover, the exposure modeling platform which can be used for personal/population exposure assessment and accessed/applied by international scientists will be demonstrated. This exposure model consider ambient air pollutant levels, local emission characteristics as well as time-activity patterns of the subjects. The combination of micro-sensor devices and exposure modeling is an exciting frontier of exposure science and environmental epidemiology research.