Precision sowing machine having a body (10) consisting of a distribution cover (11), a small distribution body (12) containing a distribution bell (13) with which at least a holed disk (19) is associated, the whole in axis with a central hole to suck in the air. The distribution bell (13) and the holed disk (19) are associated thanks to the collaboration of at least a magnetic element with at least an element made of magneto-sensitive material.