PURPOSE: To suppress concentration of dust-laden gas flows, improve dust collecting efficiency and enable the device to be operated with a minimum static pressure by providing resistance devices to the cleaning gas outlet parts on the outlet side of the respective filter cloths and make the opening of their vent parts adjustable.

CONSTITUTION: Dust-laden gas is introduced through inlet 22 into the dust-laden gas chamber 3 of a dust collecting chamber 1 and is made to an approximately uniform flow by an impingement plate 21. This flow is dispersed and fed to each filter cloth 9, whereby it is filtered. The purified gas passes through an outlet part 7 and opening 12 and enters the inside of the box bodies 14 of resistance devices 11, thence it passes through the vent parts 15 having been adjusted to the specified opening by adjust plates 17 and enters a clean gas chamber 4, from where it is exhausted through outlet 23. Deposited dust is shaked down by the high pressure air which is injected as backflow air through valves 19. Next, when filtration begins, the vent parts 15 have beforehand been adjusted narrower than the clean gas outlet part 7 and therefore the increase in the influx of the dust-laden gas to the filter cloths 9 is suppressed and omission in blowing of the dust may be prevented.