To provide a powder compaction method comprising compacting a raw material powder into a compacted body, wherein even when the compacted body has the shape of a simple cylinder or of a pipe with uniform inside and outside diameters, the formation of a neutral zone can be effectively prevented and consequently a compacted body with a uniform density throughout the entire region can be obtained.

A helical groove 14 is formed throughout the entire internal circumference of the recess 13 of a die 11. In addition, a helical tooth 20 is formed around the entire external circumference of a lower punch mount 19. The helical groove 14 is always kept in thread engagement with the helical tooth 20. When the raw material powder 1 packed into a cavity 28 is compacted by means of the upper punch 29 and the lower punch 17, the die 11 descends simultaneously with the descension of the lower punch 29. The die 11 rotates about a rotation axis being the axis 12a of a die hole 12 because of the thread engagement of the helical tooth 20 with the helical groove 14, so that the raw material powder 1 is compacted.