PURPOSE: To prevent damage of a grain improved in its conveying efficiency by forming a grain sliding fall-preventing stepped part along the diametric direction of a turning shaft in a helical blade in its upper part surface.

CONSTITUTION: A vertical feed screw conveyer 1 is integrally turnably constituted mounting two or more screw unit members 10, integrally molded by a synthetic resin material, to be externally fitted continuously along a rotary supporting shaft 11. A helical blade part 9 integrally forms in its upper surface part 9a two or more stopper protrusive streaks serving as a grain sliding fall- preventing stepped part 12 along a turning shaft part 8 in its diametric direction with a predetermined pitch. Accordingly, by the constitution thus obtained, efficient grain lifting conveyance can be performed by preventing grains from sliding and falling. While the helical blade part 9 forms its peripheral end edge to be swollen obtaining an almost circular sectional shape, enabling the large size grain of soybean or the like to be prevented from being given damage due to the grain being put between a conveyer peripheral wall 13 and the end edge of the blade part 9.