To provide a stock material feeder for use in an automatic vertical and multiple-row packaging machine capable of preventing an insufficient weight of contents in a packaging bag by sealing a powder stock material not to come out of a measure.

In the stock material feeder for use in the automatic vertical and multiple-row packaging machine, a distribution hopper 3 is provided in the vicinity of the measure 18 of a slide supply disk 7, a spring lock member 4, a spring member 5 and a gap closure member 6 are fitted into a lower end tubular part of the hopper 3, and the member 6 closes a gap between the hopper 3 and the disk 7. The measure 18 of the slide supply disk 7 is thereby filled reliably with the powder stock material, and it does not come out of the measure 18 even if the material rubs itself and static electricity is generated.