A device for storing a weft yarn for inserting in a jet loom comprising a surface which moves in one direction and retains a weft yarn thereon between a yarn-receiving position and a yarn withdrawal-start position spaced away from said yarn-receiving position in said one direction, and a feed nozzle which ejects said weft yarn together with fluid onto said weft yarn retaining surface at said yarn-receiving position, said fluid ejected from said feed nozzle impinging upon said weft yarn retaining surface at an impingement point, characterized in that a narrow blocking means extending transversely of said direction of surface movement for blocking said ejected fluid from the area of said surface downstream of said point engages said surface at a position slightly displaced from said impingement point and for a short distance therebeyond on the side thereof towards said start position where a weft yarn withdrawal operation is started, said narrow blocking means permitting said yarn, ejected on to the latter, to pass thereunder, said yarn when retained on said surface between said narrow blocking means and said withdrawal-start position being free of pressure against said moving surface.