Do we really obtain reliable elemental abundances for supergiant stars?

We discuss the problems of standard spectroscopic analysis of intermediate mass supergiants and propose the usage of Fe II lines for the microturbulent velocity and gravity determination, instead of Fe I lines that are usually applied for this aim, but more affected by non-LTE effects. With the example of delta Cep (seven high-resolution and high signal-to-noise ratio spectra) we demonstrate that the proposed approach results in the following advantages: 1 it removes the long-standing problem of the discrepancy between the spectroscopic and physical gravities (based on the estimated stellar masses and radii), resulting in a complete agreement between these values; 2 it brings the abundances of some elements (among them carbon, nitrogen, oxygen) in accordance with the theoretically predicted atmospheric abundances for the supergiants of intermediate masses after the first dredge-up phase; 3 it allows us to keep an ionization balance of some elements observed in two ionizational stages together with the Fe I/Fe II balance.