Recently, sputter etching with low energy ions of sub keV region has been strongly required for the high resolution depth profiling of shallow junctions in semiconductor devices. For this we have developed a compact floating type low energy ion gun (FLIG) which can be used for the sputter Auger depth profiling. The FLIG system consists of a permanent magnet aided electron impact type ionization cell, an extractor, and a cylindrical retarding immersion lens system. An Alnico-8 permanent magnet was mounted in the ionization cell, increasing the ionization efficiency by two orders of matnitude more than same ion gun without a permanent magnet. Performance of this FLIG system was examined.