Abstract Particle Induced X-ray Emission(PIXE)analysis is one of the analytical methods for elements. PIXE has high sensitivity, multi-elemental and non-destructive characteristics and the advantage of micro-beam scanning ability on the sample surface. In 1999, micro-beam scanning PIXE system was installed at the National Institute of Radiological Sciences (NIRS). The system allowed multi elemental mapping on 2mm x 2mm areas of small samples such as fish scales, small fish eyes, pollen etc. with a special resolution of about 1mu m with accelerated proton micro-beams produced by an electrostatic accelerator, Tandetron (Model 4117MC, High Voltage Engineering Europe Co.) and a micro-beam scanning system (Model OM2000, Oxford Micro Beams, Ltd.). Fine ring structure of a fish scale was observed with P and Ca maps. Pollen was examined to ability of the system to draw elemental distribution maps of singles cell. The distribution of elements in a thin section of Medaka eye was investigated in connection with Scanning Transmission Ion Microscopy (STIM)
