Taking chicken Ovalbumin as a prototypical example of a eukaryotic protein we use high-resolution native electrospray ionization mass spectrometry on a modified Exactive Orbitrap mass analyzer to dissect qualitatively and semi-quantitatively 59 proteoforms in the natural protein. This variety is largely induced by the presence of multiple phosphorylation sites, and a glycosylation site that we find to be occupied by at least 45 different glycan structures. Mass analysis of the intact protein in its native state is straightforward and fast, requires very little sample preparation, and provides a direct view on the stoichiometry of all different co-appearing modifications that are distinguishable in mass. As such this proof-of-principal analysis shows that native electrospray ionization mass spectrometry in combination with an Orbitrap mass analyzer offers a means to characterize proteins in a manner highly complementary to standard bottom-up shot-gun proteome analysis.