In recent years, dietary supplements have become widely available in convenience stores and supermarkets. They are defined as food products that promote and maintain health and are used to improve disease prevention and enhance immunity. They are available in various types and forms, including tablet and powdered supplements, and processed herbal products, etc. Among these are products that are subject to safety standards that address the presence and concentrations of heavy metals, etc.Analysis of toxic heavy metals such as As and Pb is typically conducted using an emission spectrophotometer (ICP) or atomic absorption spectrophotometer (AA), however, these require timeconsuming preparation procedures. For analyte quantities ranging from a few to tens of ppm, measurement can be conducted using an X-ray fluorescence spectrometer, which permits very easy sample preparation.Using an energy dispersive X-ray fluorescence spectrometer, we conducted quantitative analysis of As and Pb in a dietary supplement (herbal medicine), and evaluated their lower limit of detection and quantitation, respectively.