To provide a force-fed air uniform flow blowoff device of simple structure easily manufactured and installed on the spot and capable of obtaining a uniform air current with no break in a stabilized air direction and obtaining sufficient air capacity and pressure.

The force-fed air uniform flow blowoff device comprises at least a pipe 3 closed on one longitudinal end 3a side and having an opening 2 on the other end 3b side; a plurality of air passages 4 of almost the same shape continuously provided in a wall surface 30 of the pipe 3 reaching the one end 3a side from an installation part 3c spaced by a predetermined length from the opening 2; and an air capacity regulating plate 5 installed in the pipe 3 to freely regulate the capacity of air passing through each pipe side opening 4a of each air passage 4. A distance between the air capacity regulating plate 5 and each pipe side opening 4a of each air passage 4 is regulated to make air flowing out of each external opening 4b of each air passage, into uniform flow 6.