To remove the air mixed in a packaging bag efficiently.

An endless belt 2 for pressing is placed above an endless belt 1 for transporting. At the inside of the endless belt 2 for pressing, a plurality of pressing rollers, 3a, 3b... for pressing the endless belt 2 for pressing toward the endless belt 1 for transportating are positioned at roughly the same intervals. A pair of the front and back pressing rollers 3a, 3b are to be supported through a swinging bar 8 by a portal shaped roller support member 10 which is always energized downward by an air cylinder 5. The roller supporting member 10 is joined freely swingable to the piston rod 6 of the air cylinder 5.