PURPOSE: To pack a container with powder at high speed and in a high density without damaging it by installing in a decompression chamber a container-holding device which vertically moves the container so as to fit its opening airtightly under a powder supply funnel and to separate the two alternately, a pressure-reducing device for the decompression in said chamber, and a means for raising the pressure in the decompression chamber.

CONSTITUTION: After closing an on-off valve 12, a container 80 is mounted on a support stand 62 in a decompression chamber 20 by separating the lower half body 22 of said chamber from the upper half body 21. The lower half body 22 is raised to be joined with the upper half body 21 and by closing an on-off valve 52 the inside of the decompression chamber 20 is made airtight. The opening 81 of the container 80, which is to be fitted under a toner hopper 11 at its lower periphery is positioned apart a fitting part 21b as yet and the container 80 communicates with the decompression chamber 20. After opening an on-off valve 42, both the container 80 and the decompression chamber 20 are evacuated by actuating a vacuum pump 44, and then the on-off valve 42 is closed and the vacuum pump 44 is stopped. The support stand 62 is raised so as to fit the opening 81 airtightly to the fitting part 21b. Upon opening the on-off valves 12 and 52, the toner in the toner hopper 11 pours down into the container 80. With the pressure balanced between the inside and the outside of the container 80 at this moment, an increase in pressure in the inside of the container 80 does not damage the container 80.