A dust collecting treatment apparatus is connected to a dry type polishing apparatus, sucks dust-containing air from the dry type polishing apparatus, and separates the dust and the air from each other. The apparatus includes a cylindrical main body connected to the dry type polishing apparatus; a suction box disposed on an upper plate of the cylindrical main body, a suction source connected to the suction box through a ventilating duct, a filter unit that includes a flange section supported on the upper plate of the cylindrical main body, a pipe formed integrally with the flange section and formed of a plurality of minute holes, and a filter formed of a water-soluble material and externally fitted to the pipe in a detachable manner. The filter is disposed inside the cylindrical main body. A water jet nozzle is disposed inside the suction box and jets water into the filter unit.