We have measured the 3p→3d core transition spectra of Cr, Mn, Fe, Co and Ni by the energy loss of ∠20 KeV electrons with energy resolution of 0.1 eV. As is well known from atomic physics, a discrete or localized state which is hybridized with a continuum gives rise to a distinctive dispersive lineshape. We generalized this lineshape theory to apply to the solid state. The spectral shape of Cr shows the usual Fermi edge and extended structure of normal metals, indicating that it has no local states while those of Mn, Fe, Co and Ni have a dispersive shape showing that they have local states. This confirms that a purely itinerant (Stoner) model of ferromagnetism is incorrect, even for Ni, and agrees with the model that ferromagnetism arises through the coupling of localized d l electrons by exchange polarized itinerant di electrons. The width of the localized states gives a measure of the hybridization of the d l states with the itinerant di and 4s states and continuum εf states through Coster‐Kronig transitions.