Agricultural machine comprising: a plurality of drilling units each comprising: a support device a seed metering device to distribute seeds to a drill furrow in the ground across which the agricultural machine moves, wherein each drilling unit is movably connected with a structural member of the agricultural machine and the seed metering device is fixedly connected with the support device of the drilling unit, the seed metering device comprising: a seed metering element that, by means of a driving device, is arranged to transport seeds to a seed metering line, a chamber for seeds, which chamber is arranged to be supplied with a positive pressure from a pressure-creating member of the agricultural machine, wherein the seed metering element constitutes a wall limiting the chamber and has holes or recesses, which connect the chamber with the surroundings to develop a pressure difference and thereby attach and transport seeds at said holes/recesses of the seed metering element, wherein the seed metering element has a rotationally symmetrical shape around a rotation axis, where the holes/recesses are distributed equidistantly from each other along a pitch circle concentric with the rotation axis, characterized in that the seed metering line has an inlet in the chamber, wherein an air flow out of the seed metering device through the seed metering line is created by said positive pressure in the chamber for the transportation of the seeds from the chamber through the seed metering line to the drill furrow; in that the seed metering device has a pressure equalizing means at an area opposite to a reception area and configured to, at the reception area, eliminate the pressure difference across the holes/recesses and thereby also the force trapping the seed, the pressure equalizing means being on the non-seed-carrying outside of the seed metering element and in that the seed metering device has a supporting roll on the seed-carrying side of the seed metering element configured to support the seed metering element and to prevent the seed-carrying side of the seed metering element from contacting the inlet of the seed metering line. a plurality of drilling units each comprising: a support device a seed metering device to distribute seeds to a drill furrow in the ground across which the agricultural machine moves, a support device a seed metering device to distribute seeds to a drill furrow in the ground across which the agricultural machine moves, wherein each drilling unit is movably connected with a structural member of the agricultural machine and the seed metering device is fixedly connected with the support device of the drilling unit, the seed metering device comprising: a seed metering element that, by means of a driving device, is arranged to transport seeds to a seed metering line, a chamber for seeds, which chamber is arranged to be supplied with a positive pressure from a pressure-creating member of the agricultural machine, wherein the seed metering element constitutes a wall limiting the chamber and has holes or recesses, which connect the chamber with the surroundings to develop a pressure difference and thereby attach and transport seeds at said holes/recesses of the seed metering element, wherein the seed metering element has a rotationally symmetrical shape around a rotation axis, where the holes/recesses are distributed equidistantly from each other along a pitch circle concentric with the rotation axis, characterized in that the seed metering line has an inlet in the chamber, wherein an air flow out of the seed metering device through the seed metering line is created by said positive pressure in the chamber for the transportation of the seeds from the chamber through the seed metering line to the drill furrow; a seed metering element that, by means of a driving device, is arranged to transport seeds to a seed metering line, a chamber for seeds, which chamber is arranged to be supplied with a positive pressure from a pressure-creating member of the agricultural machine, wherein the seed metering element constitutes a wall limiting the chamber and has holes or recesses, which connect the chamber with the surroundings to develop a pressure difference and thereby attach and transport seeds at said holes/recesses of the seed metering element, wherein the seed metering element has a rotationally symmetrical shape around a rotation axis, where the holes/recesses are distributed equidistantly from each other along a pitch circle concentric with the rotation axis, characterized in that the seed metering line has an inlet in the chamber, wherein an air flow out of the seed metering device through the seed metering line is created by said positive pressure in the chamber for the transportation of the seeds from the chamber through the seed metering line to the drill furrow; in that the seed metering device has a pressure equalizing means at an area opposite to a reception area and configured to, at the reception area, eliminate the pressure difference across the holes/recesses and thereby also the force trapping the seed, the pressure equalizing means being on the non-seed-carrying outside of the seed metering element and in that the seed metering device has a supporting roll on the seed-carrying side of the seed metering element configured to support the seed metering element and to prevent the seed-carrying side of the seed metering element from contacting the inlet of the seed metering line.