PURPOSE: To surely and momentarily turn on and off a backward washing nozzle, to surely perform backward washing, to transmit a pressure of backward, washing gas to the backward washing nozzle without pressure loss and to enhance the jetting velocity, in a backward, washing device for a dust collector.

CONSTITUTION: Plural backward washing nozzles 3 as filter-elements are formed on a header pipe 7 supplied with the backward, washing gas, and a connecting rod 8 actuating a nozzle stopper 3 to turn on and off the backward washing nozzle 3 is arranged in the header pipe 8.