The present invention provides a magnetic recording medium which has a thin film magnetic layer considerably excellent in surface smoothness, and is excellent in electromagnetic conversion property. A magnetic recording medium comprising a non-magnetic support, a lower non-magnetic layer comprising at least a non-magnetic powder and a binder resin on one surface of the non-magnetic support, and a magnetic layer comprising at least a ferromagnetic powder and a binder resin on the lower non-magnetic layer, wherein when the magnetic recording medium is subjected to extraction treatment with water, 7 to 23 .mu.g of PO.sub.4.sup.3- ions are extracted per 10 mm.sup.3 of the volume of the lower non-magnetic layer of the magnetic recording medium. A magnetic recording medium comprising a non-magnetic support, a lower non-magnetic layer comprising at least a non-magnetic powder and a binder resin on one surface of the non-magnetic support, and a magnetic layer comprising at least a ferromagnetic powder and a binder resin on the lower non-magnetic layer, wherein when the magnetic recording medium is subjected to extraction treatment with water, 8 to 22 .mu.g of Mg.sup.2+ ions are extracted per 10 mm.sup.3 of the volume of the lower non-magnetic layer of the magnetic recording medium.