The particle-induced X-ray emission (PIXE) analysis has been widely used for trace element analysis. This paper introduces the characteristics of PIXE method, and some examples of analyses of environmental samples. The characteristics of the PIXE method are high sensitivity analysis, simultaneous multi-element analysis, scanning analysis, electron microscope analysis, and chemical form analysis. Two international conferences were held to discuss the problems on the PIXE method. Eighty three facilities in the world are engaged in the PIXE analysis. In Japan, the application to the material science has been made at 6 facilities. Recently, the application to biological and medical sciences has also been done. It is possible to obtain the distributions of trace elements in matrix by using a collimated beam. The beam can be collimated to a diameter of several micron with an electromagnetic lens. A PIXE spectrum of Hizikia fusiforme taken at the Cyclotron-Radioisotope Center, Tohoku University, is presented. (Kato, T.). Ishikawa,-Masafumi (National Inst. of Radiological Sciences, Chiba (Japan))
