A bag for packing powder, permeable for gases and comprising a plurality of inwards protrudent hole-forming portions. Preferably, the bag comprises a film having holes (B) of predetermined thickness (d) furnished with protrudent hole-forming portions of predetermined height (h), the height (h) of the protrudent hole-forming portions being in the range of 2 to 200, still preferably 5 to 100, times the thickness (d) of the film having holes (B). By virtue of this structure, the soaring of powder at the time of powder filling can be prevented to thereby facilitate the filling operation. Furthermore, not only is the sticking of powder to seal portion reduced at the time of sealing the mouth of the bag to thereby ensure obtaining satisfactory seal strength but also the environmental pollution by the soaring of powder can be avoided.