[en] The particle size distribution of beryllium pebbles produced by the inert gas atomization method (IGA) was investigated selecting production parameters. Fine powder under 0.1 mm is easy to produce by this method. Maximum ratio between 0.1 mm to 0.2 mm to total powder amount was about 60% in this experiment. Some irregularly shaped pebbles mixed in with the 0.1 mm to 0.2 mm pebbles. Pebbles under 0.2 mm were difficult to handle and individually inspect. The amount of oxide in the pebbles between 0.1 mm to 0.2 mm in size was 0.049 weight percent. The smaller the particle size becomes, the larger the increase in oxide in the pebbles. BET specific surface was evaluated in each size of IGA pebbles compared to REM pebbles. (orig.)