Abstract: Seed metering device applied to agricultural machines including two distal and parallel vertical shell wherein houses a vertical metering disk rotating on its axis. The disk has at least one set of annular seed cells, an annular recess opposite the inner face of the rear shell, formed by a portion of the disk wall projecting towards the front end of the rear shell, followed by a disk portion perpendicular to in the direction of the axis, continued by an oblique wall towards the back portion of the shell, where it ends in a first cylindrical bushing coaxial to the shaft. Inside the recess is formed an annular ring gear, in which the cylindrical gear engages. An annular flange defines a labyrinth with recess, followed by an oblique wall through which the shaft passes. This plate determines the separation of the inner volume of the casing into two separate volumes not communicating with each other, determining an area free of dust and seeds where the cylindrical gear and the annular gear performs.