To carry all the powder and granular materials to be conveyed by a case conveyor out of a conveyance case.

An endless chain 2 having an attachment 8 for sweeping up powder and granular materials is provided with a scraping plate 7 and a scraping scraper 13. The scraping plate 7 is like a plate, brings its lower fringe into contact with a bottom plate 10 of the conveyance case 1, and brings its outer end fringe into contact with inner faces of both side walls 11 of the conveyance case 1 to convey the powder and granular materials left after sweeping-up by the attachment 8 while sweeping up the left powder and granular materials. The scraping scraper 13 has a brush 15, which is inserted into a clearance (d) formed between the side walls 11 and the bottom plate 10 by curved faces of the side walls 11 of the conveyance case 1 to scrape up the powder and granular materials intruded into the clearance (d) onto the bottom plate 10.